windows 7 backup error "shadow copy could not be created"

For me, your message helped me by pointing at the role of the shadow copy service.

I needed to resort to a different solution, using vssadmin as suggested further below, by "Bulls eye".

Thank you for these hints - that solved my problem with these errors reported as both 0x81000037 (Windows Backup failed while trying to read from the shadow copy on one of the volumes being backed up) and  '2155348000' (Windows Backup cannot find the shadow copy of the source volume.)

->Try running the command in cmd with admin:-

  vssadmin resize shadowstorage

This gave the information I needed, together with people reporting that the backup system may easily need 400MB.

Final resolution was:

1. Start a cmd with admin rights (via start menu);
2. Give the command

vssadmin list shadowstorage

This lists the places where "shadow storage" resides, and how large these places are allowed to grow to. For me, the C: drive that I was trying to backup had only 320MB available, and reports in this forum suggest 400 - 500 MB may be necessary.

3. So give the command:

vssadmin resize shadowstorage /For=C: /On=C: /MaxSize=400MB

4. Running command

vssadmin list shadowstorage /For=C:

a few times during the actual backup shows that indeed the usage did get very close to 320MB, which probably caused the failure.

Great information BlueCue.   But most of don't have that level of technical knowledge or resources.  Do you have any advice for us mortals?  When this computer crashes with no back up Microsoft has lost another home user.

I had this problem all day yesterday.  Nothing was working.  I found a scholarly article with 11 different things you can try to resolve the problem.  I went through all the steps and realized that the problem is a Windows Management utility .dll file has been deleted by our antispyware program.  Not all .dll files are evil and this one is actually necessary. The way to tell if this is causing the problem, when you try to create a system image and save it an external device, you will get a stop error code 800423F3.

It was easy to fix and recover the dll file.

1. Go in Command Prompt as an administrator (A lot of ppl are afraid to use Command Prompt, but don't be.  command prompt is nothing more than a black sheet of typing paper. If you can find the command in a forum or tech site or book, just type it in exactly like it says-Exactly.  If you make a mistake the computer won't recognize it any way.)
2. After the command line, just type net stop winmgmt and hit enter.  It will ask you to confirm. just type y and enter.  (Another way to elicit this same effect, if you are hesitant about command prompt is go to your Control Panel and start a search for Administrative Tools.  Click on that.  Next scroll down to Services and click on that link.  Under Services, scroll down until you see WMI or Windows Management Instrumentation.  It will show it as running, look on the upper left hand side of that screen and click stop or pause.  You are stopping WMI from running for now.
3. If you are not already in command prompt mode, get into it after you have stopped or paused WMI, and type after the command prompt, regsvr32 wmiutils.dll and hit enter.  You should see a pop up that says you have successfully recovered or registered the .dll file.

4.  Next, while in command prompt, type net start winmgmt and hit enter.  (Alternatively, you can go back in to Control Panel-Administrative Tools-Services-Windows Management Instrumentation and click on Start to start it back up.  Either way, you should see beside WMI "running".

5.  Also while you are in Administrative Tools-Services-scroll to the "Vs" and look for Volume Shadow Copy.  It may have been toggled off by some strange coincidences.  It should also say "running".  If it is not, look on the upper left hand corner of the screen and click on start.  For some reason VSS had been cut off in my system.  I don't know how.  I never knew how to access all of this until yesterday which makes me think that malware or a virus had attacked all of this.

6.  After making any changes, restart your computer. I got a little scared at this point.  It seemed like my computer was taking a really long time to restart, but when it did everything was working fine.

Another thing, when you are getting ready to burn an image or do a back up to your external HDD, temporarily disable your antivirus and firewall software.  In my case I'm running ZoneAlarm.  Sometimes your antivirus and it's back up capabilities will trump your Windows back up VSS application. But don't forget to go back and restart your antivirus/firewall. 

I was able to go back and burn a system image to my external HDD.

Here is the link to the article I read:

http://backupchain.com/en/vss-troubleshooting-guide/ or do a search for Volume Shadow Copy Service (VSS) error troubleshooting guide.  This worked.  I even contacted Microsoft's Online Help chat and their tech couldn't identify or fix the problem.  They were going to escalate me at the cost of $149 which I don't have.  I'm glad I did my homework and researched this first.  Just follow the steps in the article carefully and step by step.  I was able to fix the problem.  If I can, anyone can.