First question: Do you have McAfee installed (or WAS it ever installed)? If so, keep reading. For those of you who don’t have McAfee, this article may help you – check and see if the file %windir%\system32\wuauclt.exe exists. If it doesn’t keep reading.
McAfee at some point decided that the factory SP1 Vista System file c:\windows\system32\wuauclt.exe in VISTA was a virus. On a system I was recently working on, I kept banging my head on the wall wondering what had happened to the Vista system in question. No matter how you tried to apply Windows Updates, it would immediately fail with the error code 80070002. The system was a Dell with the factory McAfee security suite installed.
After trying many fixes from multiple Google searches, such as removing pieces of c:\Windows\SoftwareDistribution\Downloads & Backup, Windows Updates still wouldn’t work. Somewhere I stumbled on someone who had this same issue – it turns out McAfee will quarantine that file thus removing your Windows Update capabilities.
The fix is simple: restore the c:\windows\system32\wuauclt.exe from your Vista DVD or if you still have McAfee installed, un-quarantine the file.
In case you are lazy like I am, I have provided a SP1 version of the file at the end of this article which you can put into place instead of restoring from the DVD. I have many computers on Vista and I just took the file from a working setup (Service Pack 1) and copied it in. As soon as I replaced the file everything was right in the world and the computer started updating again.
One more reason to hate McAfee products.
I’m so glad this article is helping people with the fix! I remember that day spending 5 hours on that computer and wondering why no one had posted a solution elsewhere!