USB booting :: video error

when i tried to run DSL on my usb pendrive on a computer, it said unspecified video mode, press return to select one or space to continue. what does this mean?
the computer is a Dell, if that helps anything

It means your video card does not support the video mode DSL tried to use.

Most commonly this means you have a vesa 1.2 card when the high-res framebuffer modes need a vesa 2.0 card. If you get this prompt, pushing 0 should always work, it's the 80x25 text mode from the age of dos..

It just means that your monitor doesn't support "normal" vga mode (or 791 if off the livecd). See the wiki for vga= cheatcodes (or fb* labels), or just select one upon boot.

original here.