Gta iv screen artifacts please help

[machielste]

In game I see horizontal artifacts across the screen the collors are not distorted.
When I record my gameplay of gta iv with faps and watch them back I cannot see the artifacts anymore.
I believe this is a problem whith my screen.
If it was a GPU problem the artifacts whould have been recorded with fraps .
I will try to play another game and see if the artifacts continue in that game.

My system specs are

Graphics card: NVIDIA GT 220
CPU: Intel q 8200
RAM: 4 GB of DDR2 ram

I cannot see artifacts in the NVIDIA control panel when I look at the spinning nvidia demo symbol.

I have tried different refresh rate settings v sincronise also doesn't work it isn't screen tearing .
I have never had the distortions before I have overclocked my GPU though it's possible the GPU has been damaged ?

Please help me with this

Thanks in advance, machiel sterenborg

 

[machielste]

I've also tried a 3-D Mark 06 at default clock settings, i noticed way less distortion,
but I still saw lines from time to time please help me with my problem it would be greatly appreciated, thanx in advance machiel

 

[machielste]

on the desktop I can also see lines from time to time they are very faint but they are visible