Last Known Good Configuration to use the old registry.
If you must, boot to the Command Prompt and run RSTRUI.EXE
You won't be the last to blow up a machine with that software.
Okay, so i used reg mech to compact my registry on XP and it was ok, prompted me to reboot BUT, when i rebooted, it show only black screen on log in screen!!!
Now i cant use my XP! help pls on how to restore it!!!