Microsoft Recently released a Service Pack for Windows 7 and it has worked fine until it has been made available via WSUS/Windows Updates for Automatic Install. It has been known to cause a few problems where the system has halted upon startup with a Fatal Error as shown below:
Fatal Error C0000034 applying update operation (Update 282 of 103814)
Many people have turned to re-building the system but there is a fix to getting the system back up and running and it is as follows:
1) When your computer starts up, choose the option "Launch Startup Repair"
2) When the Startup repair starts, click cancel.
3) After you click cancel it will show a box. Click "Don't Send"
4) Click the link "View advanced options for recovery and support
5) You may be asked to authenticate as the local administrator
6) In the new window click Command Prompt at the bottom.
7) In Command Prompt type this and press enter: %windir%system32notepad.exe
8) Notepad will open. In notepad go to File-->Open.
9) Change the type of files notepad views from .txt to All Files
10) Now in Notepad, go to C:Windowswinsxs (or whichever drive Windows is installed on)
11) In that folder, find pending.xml and make a copy of it
12) Now open the original pending.xml (It may take a short time to open as the file is fairly big, also editing you may find the process a bit slow but be patient)
13) Press CNTRL+F and search for the following exactly: 0000000000000000.cdf-ms
14) Delete the following text (you will find it may appear a bit different on your file)
<DeleteFile path="SystemRootWinSxSFileMaps_000000000000000 0.cdf-ms"/>
<MoveFile source="SystemRootWinSxSTempPendingRenamese56 db1db48d4cb0199440000b01de419._0000000000000000.cd f-ms" destination="SystemRootWinSxSFileMaps_00000000 00000000.cdf-ms"/>
Your PC might not have all 3 sections of code (<Checkpoint>, <DeleteFile>, <MoveFile>). Just make sure you delete section "Checkpoint" and whatever other sections have "000000000000000.cdf-ms". They will be right next to eachother.
15. Save the file, close notepad, close command prompt, restart your computer.
Once your computer starts up, do a normal startup (it may stall for 5-10 minutes at the "starting windows" screen, but leave it going) and the Service Pack will install some more stuff and restart a few times and then everything should be working! For some people, it reverts everything and cancels the service pack installation. For other people, the service pack installation completes. Either result is fine.
I am not 100% sure on the reason behind why this has happened, but i am on the case testing a few machines that were borked as to what they were missing compared to ones in which worked. I think it maybe this pre-requisite http://support.microsoft.com/kb/976902
I hope that helps,