exit to desktop?!?!

[hardc0re_tid]

why oh why do my games exit to desktop, ok maybe not EXIT but in the middle of a game e.g Driver PL, CSS, HL2, FarCry, i could be playing away and the next i know, im back to desktop with the game showing in along the task bar, click on the tab to open the game, black screen and the game music, them back to desktop?

would i be wise trying to run the game with only 1 core?

system spec:

e6300 @ 3.15
2gb geil ull 6400
7900gto

 

[hardc0re_tid]

it has only started to occur recently, even after a full format and fresh install of xp pro w/sp2. latest nvidia drivers 94.24

edit:

even with afinity set to one core cpu0, it still crashes.