Won't boot?
 

I installed slackware correctly(I think) from the isos. Then when I boot it says "GRUB" with a flashing cursor after it. I can't type anything on Ctl+Alt+Delete to restart any ideas?

You need to wipe your MBR as Slackware doesn't install the grub loader and its most likely leftover from a previous Linux install.

Boot up with your Slackware cd by doing this at the boot prompt it will come to:

linux root=/dev/hdXX

Where XX is the letter and number you installed your root partition to during the install.

That will get you booted into your system and you can fdisk your MBR, and reinstall lilo to it, etc.