Sudden problems with my games?? anyone care to help?

[koolaidjuice]

hey guys...so just recently ive been having some catastrophic problems with the games i play, which are as of right now NEED FOR SPEED SHIFT and METRO 2033...

i began playing this games about last week and everything was perfectly fine...playing them on max settings....now for some reason both these games are crashing constantly! In Metro 2033 anytime i throw a granade and it explodes the game would just CRASH...and even when im walking around and get to a place where theresd alot of eyecandy the game would just crash. And now its doing it with NFS shift as well..

it seems however if i drop the settings too the absolute minimum i can play with no problems....but i have a 6870 and i refuse to play every game on minumum settings!!

here are my specs....

Dell Vostro 230 core 2duo E7500 @2.93Ghz
K-power 680 watt PSU
148GB harddrive (i have 70GB left of space)
XFX Radeion 6870 HD
4GB of RAM

also..just as i type this my computer has just RIGHT NOW developed a very high pitched noise thats giving me a headache right now! i dont know what this sound is and never heard it before ever until literally right now..

can anyone assist me? whats going on? almost as if my computer or GPU is horrbile defective in someway...help!!!

 

[koolaidjuice]

P.S. yess i have the updated drivers and no i do not have any viruses