Linux not booting due to graphics issues

I'm trying to boot Ubuntu from a CD but it dies part way through claiming a graphics issue. I'm running an 8800gts 320mb. Any idea what its issue is? Knoppix won't run at all.

I'm no Ubuntu expert, but try booting from your CD into rescue mode, and seeing if you can run the program that configures Xwidows again, to see if you can select a new video card driver.

I don't have exact instructions for that distro, I am afraid.

Thanks, I'll look into it.