Why do my games keep crashing

[yoman35]

About a year ago i built my computer and had no problems at all. Maybe 6 months ago i started having trouble with my games, i would start to play when all of a sudden the screen went to some weird screen with vertical lines of usually 2 colors going down the screen and whatever sound was being played in the game would loop and play over and over. Ive probably spent more time troubleshooting then actually playing games these last few months, im pretty sure ive tried everything. Things ive tried:
Increasing the fan (not a temp problem)
reinstalling graphics card
overclocking in any and every way you could possibly think of
cleaning all the dust out
running torture tests (no errors)
switching monitors
check my power supply (its plenty enough)
and a few other things

For about the last month i havent had any issues at all but now all of a sudden the crashes are coming back. i havent changed anything or done anything different so im not sure why.
Games it Happens to: CODMW2 , Mass Effect 2 , Borderlands.
Games that work: Assassins creed , ETQW , FO3 , L4D2

I noticed that all of the games that dont work i got on steam, could this mean anything? but l4d2 was also purchased through steam but it works.

System Specs:
AMD Phenom 9950 Quad-Core Processor 2.60 GHz
8gb ram
Windows Vista 64 bit
ATI Radeon HD 4850

Im really confused and would really appreciate any help.

 

[EXCellR8]

What driver set are you running? Catalyst 10.1 is the latest I think.

Is DirectX up to date? What happens if you try to run games in DX9 mode?

I wouldn't try messing with the clocks unless you're looking for additional problems. If the card doesn't work well on factory settings then it's rarely worth your time to experiment with clock speeds. Vertical lines can point to faulty video memory, and although you may not experience problems in some games, the card may be going south.

 

[yoman35]

Yes, im using catylst 10.1 driver, and ok ill stop messing with the clocks. yeah, i just updated to directx 9.28.1886 i think its called, the latest one i know that much. and no i havent tried to run games in dx9 mode, how do i do that and what is it?

 

[EXCellR8]

sometimes when i run into problems running games in DX10 i will try to run them DX9. you should be able to force games to run in DX9 by adding "-dx9" to the end of the desktop icon target string (without quotes). some games even have the option available from the Start > Games window, so you can right-click the shortcut and select it.

 

[yoman35]

im sry but im sorta new to computer stuff, but what is the target string? is it just the name or something else lol?

 

[EXCellR8]

just right-click the desktop icon shortcut and select Properties from the list that appears. in the windows that pops up you should see a field that reads "Target" and there is a path where the executable file is. all you need to do is add -dx9 to the end of that path, and after a single space, and the game should run in DirectX 9.

 

[yoman35]

i did the -dx9 thing but it still crashed, im really clueless as to why it keeps crashing

 

[Ritwik7]

check my power supply (its plenty enough)

Could you specify the make / model of the PSU.

Also, if the system is crashing I would advise you not to OC the processor. Have you considered reinstalling Windows after a clean format?

 

[yoman35]

Power Supply

OCZ Technology 500w

Model

OCZ500SXS

No, i havent tried reinstalling windows