graphics card issue

[tango.charlie]

Hi I just tried running Performance Test but each time I get to the '2D graphics - Windows Interface' test my monitor does strange things. First of all it the screen went black then on a second attempt the screen when completely white and now it goes stripey. I have to restart my PC to get rid of it. Last time I ran Performance Test I had no problems and I haven't knowingly changed anything since then (3-4 months).

Any ideas?

Thanks