Hello damaztar,
Vista is in what is called a 'Mod-Auth' Tamper state. There are 2 types of Mod-Auth tampers.
1) A critical system file was modified On Disk - What this means is that the file, located on the hard drive, was modified in some way. This can be caused by random file corruption, a malicious program (spyware, malware, virus) or by manual file modification (by a user of the system). There is also a very small chance that an Update may fail in mid-update and cause this type of issue. As a safety mechanism, Updates are made so that if they fail, they roll back any updating that was done before the failure, but there is an off-chance that the roll back did not occure.
2) A critical system file was modified In Memory - What this means is the file itself (on the hard drive) is un-modified, but the code, from that file, running in the system, was modified in some way. and is usually caused by a running program that is incompatible with Vista.
Because of the Mismatched files listed under the "File Scan Data-->" line of your Diagnostic Report, (i.e. user32.dll[6.0.6000.16438]) your issue is a On Disk Mod-Auth
To resolve the issue, we need to replace the bad file with a unmodified/uncorrupted copy. We do this by having you re-install a past Update that contained that file (in your case KB925902) by following the below steps:
First, uninstall the updates:
1) Log into Vista in Safe Mode
2) Click 'Start' button, then Click 'Control Panel'.
3) Click 'Classic View' in the upper right of the Control Panel window.
4) Double-Click the icon named 'Programs and Features'.
5) Click the 'View installed updates' link in the upper right of the Program and Features window.
6) It may take some time for the list of Updates to appear, please wait.
7) Right-Click on the update 'KB925902' and select 'Unistall'.
8) Reboot into Normal Mode
Now, reinstall the updates:
(At this point, Vista may or may not be in reduced functionality, the below steps assume that Vista is in reduced functionality)
9) Log in to Vista and select the options that brings up the Internet Browser.
10) Go to http://www.microsoft.com/downloads
11) Search for KB925902
12) In the search results, click the update that has "KB925902" in the name.
13) Click the 'Download' button.
14) You will be given the choice to Save or Run, select Run
15) Reboot 2 times.
If no KB925902 Update was installed on your computer, I suggest running a Anti-Spyware/Malware and Anti-Virus program to see if this issue was maybe caused by a malicious program modifing the file.
And lastly, if none of these suggestions resolves your issue, open a (no cost) support request at http://go.microsoft.com/fwlink/?linkid=52029 for additional assistance.
Thank you,
Darin Smith
WGA Forum Manager
