Well I got my RMA'd Gigabyte 8800GT OC 512MB back from Overclockers, they couldn't find fault with it. So that was a waste of time.
Whilst it's been away I put my old 8600GT back in and as it happens it runs on 169.25 drivers in my Vista HP 64x system.
So this afternoon I swapped back the cards.
I uninstalled Nvidia in control panel and then booted into safe mode and ran driver cleaner.
Then I switched off the power and put in the 8800GT, booted back into safe mode and tried to install 174.44 drivers but with no luck.
I get a message saying that I'm trying to use a 32 bit uninstaller on a 64 bit system and then I get a message saying my system was not 64 bit and these drivers were for 64 bit.
If I look on my c\ drive both 169.25 and 174.44 are there so if I try to run 174.44 again I am asked whether I want to overwrite it,
I tried that but it just gets me the same "wrong version of uninstaller" and then the message telling me my system is "not Windows Vista (64 bit). This setup program and associated drivers are designed to run on Windows Vista (64 bit). The installer will now terminate."
I am so fed up with this graphics card and Nvidia.
Does anyone have a clue what's going on here?