I installed Compiz on Ubuntu 12.04, and the launcher and the top bar on the screen disappeared.
I tried deleting Compiz but it wouldn't let me. I tried to install Linux Mint 13, but it didn't let me do that either. Then I tried to reinstall Ubuntu 12.04, but the screen said the next:
Initializing and establishing link...
And then a little later:
PXE-E61: Media test failure, check cable PXE_MOF: Existing Intel Boot Agent.
I don't know how to fix it. I just want to be able to use my laptop again.