There is a very rare instance that may happen under Windows 7 if you upgrade your processor from a single to a dual or a dual to a tri or a tri to quad core processor. Under Windows Task manager > Performance tab you may encounter only the previous amount of cores visible even if you have Task Manager > View > CPU history > One Graph per CPU checked off. This graph pane area which should show the equivalent amount of cores per graph is directly tied into the MSConfig > Boot tab > Advanced options > "Number of Processors" setting. You may not show the correct amount of cores in this MSConfig pull-down. Let me give an example: You install Windows 7 with a dual-core processor and have this option checked for "Number of Processors" (in Msconfig > Boot > Advanced options) and the amount set to "2" (for dual core). This setting is not mandatory to be set but some ppl do in order to force Task Manager to show 2 graphs (or 3). One graph for each processor. At a later point in time you upgrade to a Quad-core or Tri-Core processor. The OS will not read this extra core or have anything enabled to physically use this extra core(s) until the following are performed: Uncheck in MSConfig > Boot tab > Advanced Options > "Number of Processors" and exit MSConfig d/l and install an applet called EasyBCD 1.7.2 (or later, Google: EasyBCD) which supports many features of Windows 7. Go into Advanced Options in EasyBCD and select "Limit Widows to '0' CPUs (Leave 0 to reset)". Click "Apply Settings" and exit EasyBCD. NOTE: This will force the OS to reset the count to default for the amount of Cores you now have. There is possibly a boot setting that can be added that I may not be aware of to do this same function but this little applet works and does the same thing. Don't muck around with any other setting in this utility if you don't know what you are doing it may leave your computer unbootable and a complete reinstall or long repair may need to be performed. Just make sure this one setting is set to "0" Completely shutdown the OS (not reboot or restart or logout). Correctly Shutdown you computer so the it powers down. upon restart into the OS the Task Manager > Performance tab should now show the correct amount of per core graphs if you have the "One Graph per CPU" option selected. Yay your back in business =) Notes: Some of these discrepancies will appear if your OS is reading the incorrect amount of cores. Device Manager will show the correct amount of Cores for the PC after the new CPU is installed even tho Task Manager still shows the old amount of cores. This is why you need to preform these steps above to fix this disparity and enable the OS to work with the new additional core. CPU-Z (Google: CPUID CPU-Z) will show an incorrect amount of cores until you preform the above steps. SiSoft Sandra (Google: SiSoft Sandra) will show the correct amount of Cores for the PC after the new CPU is installed even tho Task Manager still shows the old amount of cores. This is why you need to preform these steps above to fix this disparity and enable the OS to work with the new additional core. Reinstalling Windows 7 with the "Upgrade" (not Custom Option) will not fix this issue until the above steps are performed. The reinstall should clear the "Number of Processors" setting in MSConfig but it doesn't! Hence the need to run the above steps and avoid a reinstall which takes greatly more time and still does not fix this issue. In a dual boot (XP/Win7) PC, the XP Task Manager will show the correct amount of Cores in Task Manager > Performance tab even tho the same place under Windows 7 will not! Hence the need to perform the above steps. This is a rare issue, but if you are upgrading CPUs in the future these are a very important steps to enable your Win7 OS to take advantage of this extra core you are buying. Even tho in places like Device Manager it will show the correct amount of cores the MSConfig setting will override the Device Manager only allow you to work with a lessor amount of cores thereby limiting your CPUs true potential preserving your good investment. Good Luck! I hope someone who encounters this issue finds their way here after a CPU upgrade or they may rip their hair out and I can tell you from experience I was making the Level 3 tech support at Microsoft rip their hair out when I found this issue lol I was getting an Experience Index value for Processor of 6.3 when this core was disabled and not showing up in Task Manager > Performance tab. Once the above steps were performed my Performance Index jumped to 6.9! My old Dual-Core CPU was an Experience Index of 6.1 to show you the difference a 3rd core can add to your system. In the future, once I start gently Overclocking my new Triple-core processor (once I get a better CPU cooler) It should exceed 7.2-7.4 or greater Experience Index. =) TCsenter wrote also: Some recommendations (make sure you are running as Administrator): Run MSConfig -> Change to Boot tab -> Advanced Options -> "Number of Processors", make sure there is no check mark. Delete processor entries listed in Device Manager, then reboot and allow Windows to redetect/reinstall them. In BIOS, check for an option named Max CPU ID Value or CPU ID Max Val and make sure its set to disabled . This option is only provided for OS prior to Windows 2000. Save and Exit BIOS. Check for a BIOS update for your system or motherboard. Confirm the CPU model is supported by the motherboard

How to Reset the Number of Processors-Win 7, without using Easy BCD Monday, May 02, 2016 2:12 PM How to reset the number of Processors in Windows 7 operating system - (procedure will vary slightly for later operating systems), without using Easy BCD. Start->Control Panel (Small Icons), click on System, in the left pane of the system dialog box, click on "Advanced system settings" to bring up the System Properties dialog box. On the Advanced tab of the System Properties dialog box, click on "Environment Variables". Under System variables, left click "NUMBER_OF_P…" to highlight and click "Edit". In the "Edit System Variable" dialog box, change the "Variable value" to the desired number of processors and click "OK", as required, when closing the various dialog boxes. Restart your computer. Next; "Start", index "msconfig" in the search box - (or click on "System Configuration") to bring up the System Configuration dialog box. On the boot tab, click on "Advanced Options" to bring up the "BOOT Advanced Options" dialog box. Ensure that there is no checkmark in the "Number of processors" check box, click "OK" as required when closing the dialog boxes. Note; If the checkbox is selected, the system boots using only the number of processors shown in the drop down list. Additionally, if the amount of memory shown as being used in "Task Manager is incorrect, removing the checkmark in the "Maximum memory' checkbox allows the computer to reset the Maximum memory after the computer is restarted. The default settings on a new computer for both processor and memory in BOOT Advanced Options is; No checkmarks in the boxes. It is ok to put checkmarks in the boxes as long as you subsequently configure items correctly. If you configure incorrectly-(such as selecting the wrong amount of processor cores and placing a checkmark in the box), you will have to repeat the above steps starting with step 1. Restart the computer. After restarting the computer if, with no checkmark in the processor box, you observe a "Grayed Out" 1 listed for the amount of processors this is not necessarily of concern. For those to whom this is a concern, place a checkmark in the processor box, and select the maximum number of processors.

windows 7 home premium does not support two sockets

Easy steps Back up your data. Right click on my computer ->Device manager ->Processors->right click on processor and uninstall. Reboot the system. If this doesn't work you will need to install windows 7 again.

Peter, I tried your instructions perfectly and it didn't work for me. I have two dual cores and although device manager shows them all, task manager only shows two. I spoke with Tyan (my motherboard manufacturer) and they said it should show up in the Task Manager. They said the reason it doesn't is because I'm using windows 7 Home Premium and that Home Premium doesn't support more than 2 cores. Any truth to this? I can't find info on the ms website about it. Any help is greatly appreciated. That is TOTAL C R A P, Windows home premium is fully capable of supporting multi-core processors natively in either 32 or 64 bit install. Whomever told you this you need to call them back and tell them to go to school cause they are full of C R A P. Here is proof it supports multi-cores from a MVP moderator who says so. I found it by doing a quick Google search for "Windows Home Premium and multi-core support". Take a look a the 2nd post: http://social.answers.microsoft.com/Forums/en-US/w7install/thread/566d8e98-5ff6-41ad-bd79-593f5afa3655 I'm sure if you dig deeper in MSDN (the online Microsoft Developers Network) u can find the specific white paper on all this but I have to say your Tyan tech support rep is full of c r a p and needs to go back to school. Also, one thing I noticed is you said you have "2 dual cores". There is no such thing, you have a quad core not 2 duals. Dual means 2 and 2 + 2 = 4 last I checked. and 4 cores is represented as a quad not as 2 duals for clarities sake. You must have specificity when you are talking about components or you may loose ppl in helping them understand what you mean. Just a tip from me to u. The recognition of the quad cores is handled by the OS and I have no idea why you are calling Tyan as they will have no clue what you are even doing if they do not even know the OS Premium supports a quad core processor. Leave them out of it, they are clueless. Deal with Microsoft Technical Support if you have to by going to this link and calling them. This is the link for phone and email support form Windows Home Premium and I bet you anything they will know how many cores their OS supports, lol Use this link to get support for what I mentioning in my original Post (OP) to get the OS to see your multicore processor. https://support.microsoft.com/oas/default.aspx?st=1&as=1&as=1&tzone=300&gprid=14019&timestmp=634015831083231434&ps=1&acty=ProductList&ctl=productlist&wf=PID&trl=PID~ProductList&c=SMC&ln=en-us&prid=13193&gsaid=598988 The one thing I can say in Tyan's defense is that their motherboard may not be able to support a multi-core processor at worst case scenario. Although I doubt that but in any case, the OS is fully capable of supporting multi-cores. Not sure which Tyan mobo you have but that information Tyan should be able to provide you as to what core(s) processor their Mobo does support. Or their website should if they are worth their weight. If they can't, then god help us all, lol

Peter, I tried your instructions perfectly and it didn't work for me. I have two dual cores and although device manager shows them all, task manager only shows two. I spoke with Tyan (my motherboard manufacturer) and they said it should show up in the Task Manager. They said the reason it doesn't is because I'm using windows 7 Home Premium and that Home Premium doesn't support more than 2 cores. Any truth to this? I can't find info on the ms website about it. Any help is greatly appreciated.

HOWTO: Get Windows 7 to detect your new multi-core processor

Anonymous

There is a very rare instance that may happen under Windows 7 if you upgrade

your processor from a single to a dual or a dual to a tri or a tri to quad core processor. Under Windows Task manager > Performance tab you may encounter only the previous amount of cores visible even if you have Task Manager > View > CPU history > One Graph per CPU checked off.

This graph pane area which should show the equivalent amount of cores per graph is directly tied into the MSConfig > Boot tab > Advanced options > "Number of Processors" setting. You may not show the correct amount of cores in this MSConfig pull-down.

Let me give an example:

You install Windows 7 with a dual-core processor and have this option checked for "Number of Processors" (in Msconfig > Boot > Advanced options) and the amount set to "2" (for dual core). This setting is not mandatory to be set but some ppl do in order to force Task Manager to show 2 graphs (or 3). One graph for each processor. At a later point in time you upgrade to a Quad-core or Tri-Core processor. The OS will not read this extra core or have anything enabled to physically use this extra core(s) until the following are performed:

Uncheck in MSConfig > Boot tab > Advanced Options > "Number of Processors" and exit MSConfig
d/l and install an applet called EasyBCD 1.7.2 (or later, Google: EasyBCD) which supports many features of Windows 7.
Go into Advanced Options in EasyBCD and select "Limit Widows to '0' CPUs (Leave 0 to reset)". Click "Apply Settings" and exit EasyBCD.

NOTE: This will force the OS to reset the count to default for the amount of Cores you now have. There is possibly a boot setting that can be added that I may not be aware of to do this same function but this little applet works and does the same thing. Don't muck around with any other setting in this utility if you don't know what you are doing it may leave your computer unbootable and a complete reinstall or long repair may need to be performed. Just make sure this one setting is set to "0"

Completely shutdown the OS (not reboot or restart or logout). Correctly Shutdown you computer so the it powers down.
upon restart into the OS the Task Manager > Performance tab should now show the correct amount of per core graphs if you have the "One Graph per CPU" option selected. Yay your back in business =)

Notes: Some of these discrepancies will appear if your OS is reading the incorrect amount of cores.

Device Manager will show the correct amount of Cores for the PC after the new CPU is installed even tho Task Manager still shows the old amount of cores. This is why you need to preform these steps above to fix this disparity and enable the OS to work with the new additional core.
CPU-Z (Google: CPUID CPU-Z) will show an incorrect amount of cores until you preform the above steps.
SiSoft Sandra (Google: SiSoft Sandra) will show the correct amount of Cores for the PC after the new CPU is installed even tho Task Manager still shows the old amount of cores. This is why you need to preform these steps above to fix this disparity and enable the OS to work with the new additional core.
Reinstalling Windows 7 with the "Upgrade" (not Custom Option) will not fix this issue until the above steps are performed. The reinstall should clear the "Number of Processors" setting in MSConfig but it doesn't! Hence the need to run the above steps and avoid a reinstall which takes greatly more time and still does not fix this issue.
In a dual boot (XP/Win7) PC, the XP Task Manager will show the correct amount of Cores in Task Manager > Performance tab even tho the same place under Windows 7 will not! Hence the need to perform the above steps.

This is a rare issue, but if you are upgrading CPUs in the future these are a very important steps to enable your Win7 OS to take advantage of this extra core you are buying. Even tho in places like Device Manager it will show the correct amount of cores the MSConfig setting will override the Device Manager only allow you to work with a lessor amount of cores thereby limiting your CPUs true potential preserving your good investment.

Good Luck! I hope someone who encounters this issue finds their way here after a CPU upgrade or they may rip their hair out and I can tell you from experience I was making the Level 3 tech support at Microsoft rip their hair out when I found this issue lol

I was getting an Experience Index value for Processor of 6.3 when this core was disabled and not showing up in Task Manager > Performance tab. Once the above steps were performed my Performance Index jumped to 6.9! My old Dual-Core CPU was an Experience Index of 6.1 to show you the difference a 3rd core can add to your system. In the future, once I start gently Overclocking my new Triple-core processor (once I get a better CPU cooler) It should exceed 7.2-7.4 or greater Experience Index. =)

TCsenter wrote also:

Some recommendations (make sure you are running as Administrator):

Run MSConfig -> Change to Boot tab -> Advanced Options -> "Number of Processors", make sure there is no check mark.
Delete processor entries listed in Device Manager, then reboot and allow Windows to redetect/reinstall them.
In BIOS, check for an option named Max CPU ID Value or CPU ID Max Val and make sure its set to disabled . This option is only provided for OS prior to Windows 2000. Save and Exit BIOS.
Check for a BIOS update for your system or motherboard.
Confirm the CPU model is supported by the motherboard

Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.

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60 answers

Anonymous

2016-05-02T19:25:32+00:00
How to Reset the Number of Processors-Win 7, without using Easy BCD

Monday, May 02, 2016

2:12 PM
- How to reset the number of Processors in Windows 7 operating system - (procedure will vary slightly for later operating systems), without using Easy BCD.
1. Start->Control Panel (Small Icons), click on System, in the left pane of the system dialog box, click on "Advanced system settings" to bring up the System Properties dialog box.
2. On the Advanced tab of the System Properties dialog box, click on "Environment Variables".
3. Under System variables, left click "NUMBER_OF_P…" to highlight and click "Edit".
4. In the "Edit System Variable" dialog box, change the "Variable value" to the desired number of processors and click "OK", as required, when closing the various dialog boxes.
5. Restart your computer.
6. Next; "Start", index "msconfig" in the search box - (or click on "System Configuration") to bring up the System Configuration dialog box. On the boot tab, click on "Advanced Options" to bring up the "BOOT Advanced Options" dialog box.
7. Ensure that there is no checkmark in the "Number of processors" check box, click "OK" as required when closing the dialog boxes.
- Note; If the checkbox is selected, the system boots using only the number of processors shown in the drop down list.
- Additionally, if the amount of memory shown as being used in "Task Manager is incorrect, removing the checkmark in the "Maximum memory' checkbox allows the computer to reset the Maximum memory after the computer is restarted.
- The default settings on a new computer for both processor and memory in BOOT Advanced Options is; No checkmarks in the boxes. It is ok to put checkmarks in the boxes as long as you subsequently configure items correctly. If you configure incorrectly-(such as selecting the wrong amount of processor cores and placing a checkmark in the box), you will have to repeat the above steps starting with step 1.
1. Restart the computer.
- After restarting the computer if, with no checkmark in the processor box, you observe a "Grayed Out" 1 listed for the amount of processors this is not necessarily of concern. For those to whom this is a concern, place a checkmark in the processor box, and select the maximum number of processors.
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Anonymous

2015-07-29T18:59:10+00:00

windows 7 home premium does not support two sockets
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Anonymous

2012-12-05T11:10:52+00:00

Easy steps

Back up your data.

Right click on my computer ->Device manager ->Processors->right click on processor and uninstall.

Reboot the system.

If this doesn't work you will need to install windows 7 again.
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Anonymous

2010-02-12T22:58:58+00:00

Peter, I tried your instructions perfectly and it didn't work for me. I have two dual cores and although device manager shows them all, task manager only shows two. I spoke with Tyan (my motherboard manufacturer) and they said it should show up in the Task Manager. They said the reason it doesn't is because I'm using windows 7 Home Premium and that Home Premium doesn't support more than 2 cores. Any truth to this? I can't find info on the ms website about it. Any help is greatly appreciated.

That is TOTAL C R A P, Windows home premium is fully capable of supporting multi-core processors natively in either 32 or 64 bit install. Whomever told you this you need to call them back and tell them to go to school cause they are full of C R A P.

Here is proof it supports multi-cores from a MVP moderator who says so. I found it by doing a quick Google search for "Windows Home Premium and multi-core support". Take a look a the 2nd post:

http://social.answers.microsoft.com/Forums/en-US/w7install/thread/566d8e98-5ff6-41ad-bd79-593f5afa3655

I'm sure if you dig deeper in MSDN (the online Microsoft Developers Network) u can find the specific white paper on all this but I have to say your Tyan tech support rep is full of c r a p and needs to go back to school.

Also, one thing I noticed is you said you have "2 dual cores". There is no such thing, you have a quad core not 2 duals. Dual means 2 and 2 + 2 = 4 last I checked. and 4 cores is represented as a quad not as 2 duals for clarities sake. You must have specificity when you are talking about components or you may loose ppl in helping them understand what you mean. Just a tip from me to u.

The recognition of the quad cores is handled by the OS and I have no idea why you are calling Tyan as they will have no clue what you are even doing if they do not even know the OS Premium supports a quad core processor. Leave them out of it, they are clueless. Deal with Microsoft Technical Support if you have to by going to this link and calling them. This is the link for phone and email support form Windows Home Premium and I bet you anything they will know how many cores their OS supports, lol Use this link to get support for what I mentioning in my original Post (OP) to get the OS to see your multicore processor.

https://support.microsoft.com/oas/default.aspx?st=1&as=1&as=1&tzone=300&gprid=14019&timestmp=634015831083231434&ps=1&acty=ProductList&ctl=productlist&wf=PID&trl=PID~ProductList&c=SMC&ln=en-us&prid=13193&gsaid=598988

The one thing I can say in Tyan's defense is that their motherboard may not be able to support a multi-core processor at worst case scenario. Although I doubt that but in any case, the OS is fully capable of supporting multi-cores. Not sure which Tyan mobo you have but that information Tyan should be able to provide you as to what core(s) processor their Mobo does support. Or their website should if they are worth their weight. If they can't, then god help us all, lol
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Anonymous

2010-02-09T20:08:35+00:00

Peter, I tried your instructions perfectly and it didn't work for me. I have two dual cores and although device manager shows them all, task manager only shows two. I spoke with Tyan (my motherboard manufacturer) and they said it should show up in the Task Manager. They said the reason it doesn't is because I'm using windows 7 Home Premium and that Home Premium doesn't support more than 2 cores. Any truth to this? I can't find info on the ms website about it. Any help is greatly appreciated.
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0 comments No comments