Hi i have a prolem with my graphics card which is a gt 240, i run it on a triple core with 2gd with a 700 w cit psu windows 7. the problem is the pc shuts down when i am playing games, mainly armed assault 2 and medievil 2. this has only really been happenen recently .i have put the old driver in formatted the pc reinstallled everthing new up to date drivers . i have cleaned out the pc and it has'nt had much dust in it but i have noticed that the heatsink is a little loose not too much but you can move it slightly (don't worry) i did not move it again ! because i could have blown it . am thinking that i didn't use enough themal paste and it heating up the cpu then shutting down because am not geting the blue screen just windows shut down and the normal windows choice of starting windows normaly. i have used my old 400psu and it worked for about 2 days then the same again . i did really clean the pc out and checked for any dust thats why i think it played ok but it's back agin to it's old ways.if you can help me could you also tell me what i am looking for when telling you about the specs and motherboard and bios and what apps to get too . thank you