dan961 wroteI downloaded BT4r2.ISO last month but i gave the CD To one of my friends.I'm not going to redownload it because it's a 2gb file
Easy! Grab
Damn Small Linux (it's 50MB, that's damn small). Burn the ISO to a CD or make a bootable flash disk, and use it to execute the above plan.
With GNU/Linux there's about a million ways to do something, so don't worry too much about being locked out of your system. I've trashed enough GNU/Linux systems and there has always been a way to fix it. As a precaution, I like to keep
System Rescue CD handy for such emergencies.