I'm running winxp on a thinkpad laptop. The colour is often strange,
especially in the background: it shifts colours, it's often a funny
pink, shows circular rainbows, and shimmers. Other times it's fine-
like right now. Two days ago I turned the computer on and the screen
was black; I had to hook the laptop up to another monitor to see what
was going on. Then the next time I used it, presto! it was fine again.

Does anyone have any ideas of what might be going on?

Thanks in advance.
Veta