Right then, i'm down to a basic setup. No cards, 1 CD-ROM, 1 Hard drive.
While I was using an win98 system floppy the screen cleared unexpectedly and I managed to get some commands in. I re-partitioned the hard drive, formatted it and installed windows XP onto the blank hard drive. It worked Ok for a bit but when I turned it on the next day the problem had come back
It worked on and off seemingly at random.
As a last measure I have downloaded the very latest video driver with still no luck. Nothing I do seems to get rid of the problem.
So now when I boot up the first DOS boot screens look all scrambled, covered with exclamation marks and when winXP gets going it either comes up Ok with a high res/colour screen, or with a low res/colour screen.
I'm just about convinced that it's the video card so i'm going to give it a week and buy a cheap video card and see what happens. Its just annoying that it works sometimes and not others
If anyone thinks it could be something else please feel free to fire any suggestions, i might save me some money
Thanks for everyone's help with this, hopefully you won't hear from me again on this matter