Reformat now big problems with 5770

[JackBauer_lol]

Hello

I had to reformat my PC this weekend and now I'm having issues with my 5770. It crashes nearly every time I try to play a game. I'm struggling to even get into a game on SC2, it often just crashes at the main menu. I actually got into a game a few minutes ago and it crashed within 10 seconds.

The crashes result in either:
- verticle lines in the colour of whatever the major colour is on screen at the time (blue for sc2 menu, grey in-game due to creep)
- plain black screen

I also play SC2 on low settings to prevent any chance of lag in games so I can't see how my card is over-loaded in any way.

I ran ati overdrive auto-tune. This put it at maximum settings on the slider, I turned it down to roughly what it used to be anyway (GPU Clock @ 800Mhz Memory clock @ 1300Mhz) which is about 40-50% along the slider. Before the re-format, I ran it on settings near-exactly like these with no issues at all for several months.

I'm downloading SP1 for Windows 7 at the moment, is there any chance this could help in some way?

 

[JackBauer_lol]

Ok so when I turn off overdrive completely, it works fine.

Is there a particular reason formatting my PC would suddenly make my card incapable of slight overclocking?