I've tried to boot up into Ubuntu 9.04 but all I get is a screen that looks like a multicolored bar code.

I cant see anything but thin 1 to 2 pixel black and multicolored lines running vertically on my monitor.

Does anyone know how I can make this behaviour go away.

My computer is an HP Pavilion Slimline with an AMD athlon 64 bit cpu. It's got an NVIDIA GeForce6150SE nForce 430 display adapter and my monitor is an HP w22 Wide LCD Monitor.

This has been happening for the last several releases and it makes me sad to be stuck in windows against my will.

Thanks in advance for any heop you can provide.