gray screen

[kazoo45]

i have not seen my problem listed here.sometimes when i start my computer a gray screen appears and it tells me to restore my computer or the other option is just to start my computer.i contacted dell and they say it is not a hardware issue,but either a microsoft issue or a conflict with a program that is running on my computer.i have called microsoft many times and they say that it was a matter of emptying the junk mail(which was wrong)they checked the error codes and said that something was wrong with the c or e drive.
these are the daily steps i tAKE.
1.DISK CLEANER
2.REG-CURE
3.EMPTY THE JUNK MAIL
4DO A TUNE UP AND ANTIVIRUS SCAN ONCE A WEEK.WHICH INCLUDES A DEFRAGMENTATION AND CHECKS FOR SPYWARE.
i do not have any programs on my computer at all.but i do have limeware,which my anti-virus(microsofts all-in one-live care)detects a corrupt file and automatically fixes the problem.but even when i deleted limewire i still had the same problems.is it limewire or is it a vista issue.the problem is i do not get error codes at all.my computer is a dell 530,quad proccessor with 3gb, it has a high speed connection and speed is never a issue.help me.