Inaccessible Boot Device error in Windows 10

Crysta,

What are you saying? I don't understand almost any of your post.

From what I read the kb is to fix random reboots and unexpected behavior in specific processors by turning off the fix that broke them. Doesn't this seem to suggest this registry edit could rollback the changes that are causing the bsod?

Like I said, if someone has the bsod and can test the kb or the registry edit before testing their PC, I think it could be very helpful.

I was hopeful but I do understand Bobby, that is why I was as Simplistic as I can be/know how to be.

If this your first exposure to Boolean Algebra(it is very minimal here) and Bit Maps, it needs rereading. This is a very minimal foyer into how computers work, Bobby. 

Have you been following the evolution of the Registry adjustment that I show there. It has been across 3 or 4 KB's over about 10 days 2 weeks(time has run together a bit for me) if I remember correctly?

Simply put, the "KB4078130 in my experience, does very little. For those Folks who would just as soon not go into the Registry, it turns off  "Spectre Variant 2" or in official speak: "disable Variant 2: CVE 2017-5715"Branch Target Injection", by setting bit 1........." from the previous post.

"Spectre Variant 2" requires "fully patched with MICROCODE" installed via a BIOS update. Microcode is 'Firmware on bare metal, ie Chips in the Chipset, CPU Cores, and other chips installed on controllers/Drives/Network Cards/GPU's, etc. The Kernel accesses the Microcode through the BIOS for the Windows OS usage. Turning off "Spectre Variant 2" in the Registry, STOPS the Kernel/OS from accessing the Microcode that MIGHT, MIGHT be causing BSoD. However the BIOS and other Chips in the Chipset still have access to the BIOS and potentially the Microcode.

That is why Intel has recommend reFLASHing the BIOS to an earlier STABLE version, which, "should, should" remove the unstable Microcode.

Therefore if one HAS NOT FLASHED the BIOS for Meltdown and/or Spectre DO NOT. Wait until things have thoroughly stabilized, especially on Production PC's. It is possible for the Kernel software from earlier, January, Patches to cause BSoD without the Microcode but less likely. That patch should turn off the new code for "Spectre Variant 2". 

Keep in mind that the same Registry Keys are used for Meltdown(Bit 2) as well. If both Keys are set to 3, Meltdown and Spectre 2 will be turned off BUT there is Kernel Code in the Patches for "Spectre Variant 1" which does not require Microcode(like Meltdown DOES NOT) that will still be running merrily away, as I understand it. The only way to turn that off, again, as I understand it, is to turn off AU for WU/MU and remove all January Patches. The ONLY REASON, I would go that far is if I was convinced they were still causing my BSoD's and other instabilities.

I hope that helps, Bobby, your head is not the only one that is drowning in this morass and crap filled Sea. Intel started conceiving of this, starting in 1992.

Best Regards,

Crysta

Crysta,

What are you saying? I don't understand almost any of your post.

From what I read the kb is to fix random reboots and unexpected behavior in specific processors by turning off the fix that broke them. Doesn't this seem to suggest this registry edit could rollback the changes that are causing the bsod?

Like I said, if someone has the bsod and can test the kb or the registry edit before testing their PC, I think it could be very helpful.

WIN 10 BSOD FIX - Inaccessible Boot Device - THIS WORKS!  I Just Repaired 2 computers that went down at the same time last night on 1/16/18

Good Afternoon Bobby,

Here is the fix I came across from another kind IT tech, please see below.  Credits go to them, I'm just forwarding so everyone can finally get their computers back up and running.

Boot Windows 10

Go to Repair

Go to Tools/Options to get a command prompt.

Confirm the drive letter for the Windows image. Usually D: –> dir d:

Run the following to view the installed packages which will also show a date of install.

Dism /Image:D:\ /Get-Packages

Find the package(s) that were just installed by date. Run the following command on the last installed package:

example: dism.exe /image:d:\ /remove-package /packagename:Package_for_KB4014329~31bf3856ad364e35~amd64~~10.0.1.0

Reboot.

The patch that caused my issue was from 1/6/18 or 1/10/18     Remove the latest windows update entry with Rollup Fix in it's name.  Once complete, close command prompt, turn off computer.  Power back up.  You should be back into WIN10.

If you still receive BSOD, rinse and repeat with the next latest update, try it again.  You'll eventually boot right back into WIN10.

I hope this helps.

Have a great day.

Showster

Showster,

It worked.  Thank you, Thank you. This repaired the Inaccessible Boot Device error on my Dell XPS8500 PC.  I have Windows 10 Professional operating system. 

<moderator Susan note:  I'm going to flag this as the answer just to let folks know of a workaround.  The true answer to this is to find the root cause of the problem and ensure it never happens again>

Everyone.... 

I can say, the fix that Showster provided above seemed to work on 2 of my PCs but then I am showing updates that are being received on the 26th and 27th and removing these with the steps above have not worked.  I have now had 2 pcs that I have had to take their hard drives out and copy their user folder data, office files, etc documents, desktop, links,. etc.  their entire user profile and tell it to restore windows (keeping user files), makes it alot easier, then you just have to reinstall office and other programs they made have had.

I agree, this all is absolutely rediculous.  I am guessing that this all has to do with the Intel issue and Microsoft came out with a fix in the roll-up?  What is the cause, Microsoft Tech Support needs to get this fixed.  I have over 70pcs that are probably going to be affacted.  It seems that Windows 10 v1709 is the issue, or not that the version is, but the fixes that were released after the Fall Update.  All the fixes (Roll-Ups) after the 1st of the year is when this all started.

Does anyone have any other insight into this issue ...  January 3, 2018 seems to be the first time I seen that there was a problem or around this time.  Then after the 15th pcs here started really being affected.  Now after the 26th, again, more and more, but it seems like its getting harder to correct.

doing the DISM again fixed 2 of 8 PCs the others I was able to recover backing up their hard drive in a dock that I have and restoring windows to default (keeping user files) and reinstalling some programs, but this is crazy.  Again, with a company that has 50+ pcs...  Not looking forward to this at all...   Suggestions are quite welcome....

Thanks everyone.

Techie@KF

Can anyone try this update to see if it fixes the problem?

support.microsoft.com/en-us/help/4078130/update-to-disable-mitigation-

Based on what I read, Intel acknowledged a microcode issue and recommended everyone stop deploying the fix. I am assuming the fix they are referring to was contained in the kb4056892. So the linked kb update disables the problematic portion of the update. I don't have a machine to test it on currently. It looks like a temporary fix until they can fix the issue without crashing broadwell and haswell processors.

Download link:https://www.catalog.update.microsoft.com/Search.aspx?q=KB4078130

Bobby,

This is what I wrote for the LIST, it still hasn't been Posted yet, that I have seen.......

@Phantomofmobile on Twitter.

Hi Folks,

I am going to endeavor to make this as SIMPLISTIC as I can for those people whom don't know Boolean Algebra and Bit Maps or for those who need a refresher.

Those of you whom know this COLD, Please bare with those who don't. If you have a better way to explain this, please feel free.

Maybe we can fend off some confusion early on here. My partitions are fully patched with NO MICROCODEand no issues. I am going to describe behavior on W 8.1 but I would NOT expect any difference on any other W OS.

KB4078130in my experience, does very little. For those Folks who would just as soon not go into the Registry, it turns off  "Spectre Variant 2" or in official speak: "disable Variant 2: CVE 2017-5715"Branch Target Injection", by setting bit 1 in the Registry Key Name 'FeatureSettingsOverride' to the Value of "1" or in 'DWORD' speak "0x00000001". YourMileageMayVary if you have "Microcode" but I don't see that as a possibility. I DID NOT get any indication the the .exe Ran, was Running, or even Completed! I had to look in the Registry itself, Knowing how I had left it SET, to see the results. I also Ran it in CMDLine, same thing, nothing indicated except NO ERROR was Thrown!

In an earlier Email, that Susan kindly forwarded, Thank You, Susan, I demonstrated the very simple bit Map that we are talking about.

An excerpt from KB4073119:

​"​

Windows Client Guidance for IT Pros to protect against speculative execution side-channel vulnerabilities

Last Updated: Jan 26, 2018

To disable Variant 2: CVE 2017-5715"Branch Target Injection":

reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverride /t REG_DWORD /d 1 /f

reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverrideMask /t REG_DWORD /d 1 /f

Note disabling and enabling the Variant 2 via registry setting changes will require a reboot and administrative rights.

​"​

One needs to Restart on every change for it to take affect. It is brutal if one is testing to see the different RESULTS!

(Yes I was in CRAZY Restart Hell for over 2 hours, So you don't have too, unless you like "CRAZY Restart Hell" or are a Beta Tester like me)

From the above we are seeing in the first "Reg Add" what KB4078130 is doing but in the second Reg Add what it is NOT. It leaves****'FeatureSettingsOverrid'at "3" or in DWORD speack "0x00000003". As we see though, 'FeatureSettingsOverrideMask' bit 2 in both 'FeatureSettingsOverride' and'FeatureSettingsOverrideMa', one can MASK OFF bit 2 so that it is not affected by adjustments and changes to the bit Map for Spectre Variant 2  by making it "0". Thus for 'FeatureSettingsOverrideMa' the 'DWORD' is "0x00000001".

As far as I understand this "Spectre Variant 1" is active in the Patches from earlier in January, it is strictly Kernel Software and is "ON" all of the time. It can not be turned off.

For 'FeatureSettingsOverride' "1" is OFF.

For****'FeatureSettingsOverrideMa' "1" is Active.

Decimal: 0 (0x00000000) |  Binary Bits: 00

Decimal: 1 (0x00000001) |  Binary Bits: 01

Decimal: 2 (0x00000002) |  Binary Bits: 10

Decimal: 3 (0x00000003) |  Binary Bits: 11

Spectre is in Bit Position '1', Meltdown is in Bit Position '2'  Bits are counted FROM THE RIGHT.

I hope this clarifies some of this confusing "Mumbo Jumbo" of the Boolean Binary World, for some of you and gives those whom know all of this, an example that you can show to those who don't.

It is my guess that most will leave 'FeatureSettingsOverride' on "3", "0x00000003" for the DWORD and just vary 'FeatureSettingsOverride'

I am not advocating either way. Just keep in mind though, we are in a period of immense FLUX, and it could be that way for years?????

Hope this helps some of you,

​Best Regards,

Crysta​

Bobby,

As specified in the KB's, they are for IT Admins/DevOPS, which if I am not mistaken you're one. Others here may not be.

I do not see any indication that it does anymore that what I specified above.

Best Regards,

Crysta