so my computer was working fine 2 days ago and when i turned it on today nothing came up expect a screen full of dots ( colored small dots everywhere) and i can't see anything else and after the dots like 1 minute the pc turns off by it self
thanks in advance
I can confirm what 13th monkey wrote.
Last week my friend experienced exactly the same symptoms. After testing his Radeon 4850 on my rig, we saw identical effect. Colorful dots right from the boot of the computer. Although it didn't turn off, we couldn't install amd drivers (we ran on standard windows 7 drivers).
We bet that either gpu or (more probably) memory was damaged.
Daneel97 you gonna need new graphic card