[tomedcollins]

My problem is one that's easier to let people see for themselves rather than describe, so please look at the attached file (note that the red dots in the top half of the screen are part of the corruption).

My computer isn't permanently like this. One time it happened the display returned to normal as soon as I switched to another window, but conversely there was an occasion it happened when I turned the computer off, left it overnight, and turned it on again to find the problem still present.

The corruption isn't only present within the Windows environment - when I reboot the machine the initial text detailing information about the graphics card is corrupted, as is the Windows startup screen.

While the display is like this, the computer runs noticably slower and freezes for a second or two roughly every half a minute.

The computer itself is a P4-2000, with a Sparkle GeForce 4 Ti46000 graphics card. The OS is Windows XP Professional.

Before this problem started the computer had run perfectly well since I bought it eight months ago. I've neither added nor removed any hardware from it since I've owned it.

To try and cure the problem I ran a virus check on the machine, which showed no viruses present. I formatted the hard drive and replaced XP Home with XP Professional, and I've removed and reinserted the graphics card. When I performed the last measure the graphics were corrupted when I turned the computer off before taking the card out but were normal again when I'd completed my task and switched it back on. Everything was fine for several days but then the problem returned.

Hope that this is enough information. Thanks in advance to anyone who can offer advice, and indeed to anyone who just takes the time to look at this post, whether or not they can help me.