...using System Restore to a time before all the problems.{Click on Start-All Programs-Accessories-System Tools-System Restore. When the SR window loads, select "Restore my computer to an earlier time", then click "Next". At the "Calendar" window, select a day before your problems and follow the prompts to restore back to that day. The computer will restart itself. It should allow you to boot correctly again and start from scratch with the installations.

The next time you do any CD/DVD burning, try temporarily disabling your antivirus, the firewall, and any other programs running in the background. The "burn" will normally turn out better.

Hope this helps.