weird things happening with my computer

[Shahab6]

lately i cant even get on my computer because ive gotten so frusterated with it ive jus said fuck it, and jus used my PS3 for websurfing.

but anyways, whenever i get on the net and am looking at websites, the screen will get ( its hard to describe whats happening) pixelated, i guess is the word for it. many many multiocolored dots scramble the page im looking at and then the more i scroll up and down on the page, the worse it gets. the pages links and pics will start overlapping themselves until what im lookin at is a jumbled mess of pixels and scrambled links and pictures.

then after that happens my screen cuts out. itll go black and come back on showing the same fucked up picture. it will cut out multiple times in a few seconds and jus come back on for no reason.

now ive gone through 2 different graphics cards, and 2 different monitors and have still had problems with my picture. although its not the same problem everytime, this recent problem is new, but i have had problems in the past with my screens picture.

ive also tried redonloading the drivers for my graphics card (GeForce 6800 GS) and the problem still happens.
i dont know if i explained it good enough but any advice would be appreciated.
the monitor i use is a samsung 790DF by the way, if it means anything.