ATI 5770
One game i have actually looked at - MW2
Yesterday Maxed out - 100+ FPS
Today Lowest settings - 30+FPS
Same problem with TF2
Video play back, not HD average quality AVI, 25fps at start, full screen 10-15
Only problem i have had is my Master boot drive playing up, managed to sort it out with a chkdsk, and currenty de-fragging and Virus scan.
Halp? :<
Re-installed drivers, older drivers and reset clocks to default.