This problem, I realize, is very similar to another one here in this thread. However, because it's been solved, I can't post in that one to inquire into the solution that the person found. What is this 'clean startup boot'? I am hoping it doesn't wipe any personal data. Meanwhile, just in case the problem is somehow different, here are some details that I believe would be necessary. Feel free to ask for more if need be. I'm running a Windows 7 64-bit. Basically, whenever I try to install new Windows updates and restart the computer to do it, it would do so, and fail, then revert the changes. This has been happening for a few days now, and it's starting to get on my nerves. The error code for this one is Code 80071A90. And yes, I have seen this link: http://windows.microsoft.com/en-US/windows7/Windows-Update-error-80071A90 I ran that fix-it program from the link and it didn't help. Not sure how else to find out about what programs would hinder the updating progress. EDIT: And the anti-virus software that I use is Symantec Endpoint Protection.