Antivirus software is a must-have for most users running Windows, but sometimes, it pays to be a little more selective about antivirus updates before hitting the ‘Update Now’ button. A mandatory patch pushed out from well-known antivirus vendor AVG has resulted in some Windows 7 machines experiencing complete boot failure due to the removal of certain key system files.
If you happen to have AVG installed in your PC and run Windows 7 on your PC, you might want to check if your antivirus software had downloaded a mandatory patch sometime yesterday. If so, today might be a very good day to start making plans to recover Windows 7. This is because AVG has just announced that the mandatory patch which it pushed out to users had been confirmed to cause some PCs running Windows 7 to suddenly become unbootable after a system restart.
According to AVG, the mandatory update will request a system restart after installation is complete in order to make changes to certain files that could not be accessed because they were in use during the update process. And this is where the issue occurs: shortly after Windows restarts, users who are affected by the problem will be greeted with a rather cryptic STOP error message as shown below:
STOP: c0000135 The program can’t start because %hs is missing from your computer. Try reinstalling the program to fix this problem.
For those affected by the issue, fret not: AVG has published a list of instructions on its official forums detailing some aspects of the error, along with some steps users can take in order to restore Windows into its original working state. Those who are still able to boot into Windows 7 via Safe Mode can reverse the damage down to the operating system by running System Restore, and then subsequently re-installing AVG.
However, in the event that Windows has been damaged to a point where even Safe Mode is not usable, there are still ways to recover the PC. AVG claims that its AVG Rescue CD and the Windows 7 Startup Repair feature built into Microsoft’s latest OS will be able to fix the boot failure, after which AVG must be re-installed again.
Last but not least, AVG claims its findings indicate that this particular issue only affects 64-bit versions on Windows 7. So if your PC is not running that specific arch of Windows 7, chances are your PC is safe.
Source: AVG Official Forums