So, tell us about the 'new' computer, the 'new' gpu, and the 'new' power supply.
edit: (e8400 noted, 4gb ram noted, gtx 460 'enthusiast edition' noted) (vista noted)
edit: (this your card? http://www.pureoverclock.com/review.php?id=1065&page=5
Also tell us how hot said gpu is getting during the problem moments. Use software. There are many ways to get the temps.
Need actual make/model, etc. PNY card? But which generation, etc.
Have you ever purged the drivers using Driver Sweeper, and then reinstalled them?
Don't ignore the memtest advice previous, either. I wouldn't try to manually check the temp though... stuff cools off too quickly once you remove the heat source, and it's just easier to use software.
In particular, is it just the driver locking up and resetting, or are you getting actual video corruption? From what you posted, I'm betting lockup/reset, but no corruption this time. green and/or white 'streaks', pixels, etc.http://www.cpuid.com/softwares/hwmonitor.htmlhttp://www.piriform.com/speccyhttp://www.memtest.org/