Quote Originally Posted by leif
.... but I'm pretty sure that its the RAM or the graphic card. ...
First step, test your RAM, which you can do with the Knoppix CD. Boot the disc, and type memtest at the boot prompt. memtest86 should run. Let it run at least through a full pass of all tests, or until an error is reported.

If RAM is OK at least you know that. If it is bad you have little choice but to replace it or at least remove the bad strip if you have multiple SIMMs of memory. The good news is that memory is dirt cheap if you shop around a little (often under $20 U.S. for 4 gig!, and less for smaller amounts). You really don't want to be running with bad memory, you can corrupt data. Of course, you can pay a lot more if you don't shop for sales.

If it's a video problem and it's a notebook you may have no good way to repair it, but I would look at all of the BIOS settings before giving up. At the very least reset the BIOS to defaut settings and try again, maybe something has been changed and caused a critical timing issue.