Possible Duplicate:
Can't install Ubuntu since 10.10
I've been trying to install Ubuntu 12.04 on my computer for some time now. It works on my laptop, but won't install on my desktop. I've also tried installing 11.04, and the same problem occurs. The purple screen comes up, the orange dots load, then the screen turn into to a black and white checkerboard, and nothing else happens. I believe the issue has to do with my nvidia graphics card, as I have heard it can cause issues for Ubuntu. I am booting from a USB drive. Any suggestions?