Has anyone else tried to install WindowsActivationUpdate.exe and have it fail with "This update is not applicable to your computer"? This system is running ultimate with a 2.1 mod .. nothing special. The only other action I did was to apply the WAT Vaccine a few days ago. Prior to running the update I deleted the system32/wat dir the vaccine created. I ran the update and it failed. I then used system restore from before I used the vaccine. Running the update now claims the update is not applicable. For kicks I tried to download mediaplayer 11 which needs validation and had no problem.