Computer freezing..

for some reason my computer has been freezing while i play counterstrike source. it has never done this before and i havnt changed anything that should have started this. while im playing the game will just freeze and go to a blue screen with no text and it makes alot of wierd noises. it wont get off of the screen and i end up having to reboot. other times it will just freeze. and i have to reboot, but it makes the sound as if a error message has popped up in the background. one time i have been able to read the error message and it was something about a reference memory error and a bunch of hex numbers. im not sure if theres anything you can do to help, but i figured it couldnt hurt to ask.

hmm.. could be many different things.. how long has it been since you ran maintinance on your machine..(emptied temp files… defrag.. scandisk… etc)..? And I dont guess its stopping in the same place when it freezes ..? (I know I wouldnt be that lucky..). Also list your specs if you dont mind.. CPU.. Ram.. etc..etc

ok well now it has changed…. well first of all… i have windows xp home edition radeon 9700 pro 128mb video card 1 gig of ram 2.2ghz amd 2800+ cpu ok well now i noticed that battlefield 2 does the same thing… now on either game when i start the game it loads fine…all the menus are fine…but after loading say the map or mission im going to play it just either freezes or goes back to desktop. i dont even get an error message now. i usually clean my computer every weekend. in the last few days ive defragged, virus scanned, removed adware/spyware, registry cleaned, emptied pretty much everything i could. ive also updated my video card driver and nothing. oh and is there a way to test to make sure that a disc drive is bad?…cause my cd-rw drive hasnt been working for a while now.