Hello Craig,
The core to your particular issue centers on the line in your Diagnostic Report that reads:
File Scan Data-->
File Mismatch: C:\Windows\system32\setupapi.dll[6.0.6000.16609]
This line means that the critical system file setupapi.dll either:
a) Has been tampered/modified/become corrupt to the point that its Signature Hash no longer matches the Signature Hash listed in Vista's System Catalog.
Or
b) The setupapi.dll file has recently been updated but the file's Signature Hash was not updated, in Vista's System Catalog to reflect the updated dnsapi.dll file's new Signature Hash.
Vista compares a Critical System file's Signature Hash with the Signature Hash listed in its System Catalog to determine if that Critical System file has been tampered with.
To resolve the issue, we need to replace the bad file with a unmodified/uncorrupted copy. You can do this by one of following ways:
A) Install Service Pack 1 for Vista (http://www.microsoft.com/downloads/details.aspx?FamilyID=b0c7136d-5ebb-413b-89c9-cb3d06d12674&DisplayLang=en). I believe SP1 contains an updated version of file setupapi.dll, that once installed, should resolve the issue.
Or
B) You can re-install a past Update that contained that file (in your case update KB938371) by following the below steps:
First, uninstall the updates (if you do not have the update installed already, skip to step 9):
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 'KB938371' 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 KB938371
12) In the search results, click the update that has "KB938371" 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.
Or
C) Repair Windows using System Restore:
1) Reboot Vista into Safe Mode
2) Go to Control Panel
3) On the left hand side of the Control Panel window, Click on "Classic View"
4) Double-click "Backup and Restore Center"
5) On the left hand side of the window, click "Repair Windows using system restore"
6) Select "Choose Different Restore Point", Put a check in the box that says "Show restore points older than 5 days", select the restore point that corresponds to the date Before you first noticed the issue.
7) Click the "Next" button.
8) Reboot back into Normal mode
9) Vista should no longer be in Reduced Functionality mode
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
