Playing games my screen flickers, goes black then goes back to game

Hello, whilst playing games (mostly RTS) my screen flickers then goes black, sometimes goes to the desktop or the game loading screen then resumes the game?
My GPU is an NVidia GTS 250, I have updated the driver to the latest version but the issue still persists, the issue isnt with one particular game, it happens on Dawn of war 2, king arthur fallen champions, war hammer mark of chaos. From the sys reqs my system should be more that capable of running them.
Any thoughts would be most welcome.

Thanks,

This is the original card I built the system with, have recently updated the GPU driver but it was doing this before then, its only just got bad enough to annoy me.

Thanks,

smarteyeball said:

Just a guess here, but it sounds like it's reverting to previously loaded block in your VRAM as it's cleared to make room for new data. At least as far as the loading screen goes. (ie A breif glimpse of the old before it's out the new).
When it goes to the desktop, is it 'brief' ie just a glimpse, not usable, or does it let you fiddle with the mouse and then it automatically re-enters the game?

When it goes to the desktop its just 2-3 seconds, I can still move the mouse but the cursor is the ingame cursor(not the normal windows one).
Is there any way I can check/cure if it is what you first mentioned?

Thanks,

Thanks, will have a look on t he nvidia forums and post back if I find a solution.