Okay maybe not a big deal for some but Microsoft just completely screwed anybody looking to get a little extra performance out of your card. If your running a 32bit version of windows don't worry it does not concern you.
Okay so I had noticed the other day that Riva Tuner was not working and wouldn't load the driver because it wasn't signed. Well thats the only GPU overclocking option in Vista currently so I went on a mission to figure out why it was no longer working.
Today I finally located what causes the problem. Here are wonderful friends over at Microsoft learned of a Atsiv kernel driver that by passes Microsofts requirement for a digitally signed driver. This is how Riva Tuner used to by pass it. Well it appears on August 2nd they released a update that contained software via Windows Defender that stops the Atsiv Kernel driver from working.
Which means for us overclockers we can no longer have Riva tuner on a simple boot. There is a work around if you have already installed it. After your bios posts and your boot loader loads in your harddrive you can hit f8 and it brings up a prompt were scrolling to the bottom you can select to turn off digital signing. Basically what Atsiv Kernel driver did but its no longer going to be automatic you will have to do this everytime you load Vista if you want to load overclocked settings.
64bit owners listen up! DO NOT INSTALL THIS UPDATE!
KB932596 (It says right in the details it fix's a kernal patch lol)
Thats what screws up Riva Tuner. I just un installed it and confirmed thats the problem!
Heres the source Linky