i install 175.16 the last driver, install OK

But i open a folder, my dispaly make a short 1 second crash/distorts, than all ok, i open a second folder or close any folder crash/distorts again, its a bug or an error??

My system DELL inspiron 9400 with a 7900 GS 256MB

If you want i can make a foto, cant make a screenshot or video, you dont see this on it

I think thats the problem with with low power 3d clocks, if you increase them the problem goes away. try increasing by 25-50 both core and memory. try increasing it a little. I used to have that with previous drivers as well on my 7900gs.

I had this problem only with high drivers, the driver 163.75 run very best , no problem but the newer driver 169 and higher, i had this problem.

Yes, the problem is with the clockspeeds of the card.

You're running Vista, and that's why you have the issue. What you need to do is go get NiBiTor, "dump" (save) the BIOS currently on your card, and edit it. You need to edit the 2D Memory clockspeed, and raise it from 100MHz to 150MHz. Then, save the BIOS to something easy to get to, with a simple name.

Then, flash your card with the new BIOS, and your problems are gone.

I need to make a sticky about this somewhere...

@Fenuxx

I had the 7900gs rev 0 with the bios unlock, and the original clocks, i can overclock this, witch clocks can i take, not to mutch, but more performance in games

Its all about your 2D clocks man. Change those to prevent desktop distortion. Asking about gaming refers to your 3D clocks. It all depends on your particular card as to how far you can overclock. You definitely can and should set your 2D memory to 150 MHz (300 MHz effective). You can probably set your 3D core to 600 Mhz and 3D memory to 800 Mhz given that you have a rev0 card. Anyway, thats up to you to experiment with.

Note that using a unlocked rom is driver dependent and given that you are trying to fix the driver problem, it would make sense to dump the rom the way Fenuxx said.

Edit: I will respond to your OC question in this thread later: http://www.notebookforums.com/thread180011-25.html