I'm helping out a friend with his Studio Slim 540s.  Had a rather nasty viral infection that needed to be taken care of.  So I tried programs and they were either being blocked by the nasty or not finding anything.  So I tried in Safe Mode.  The nasty still came up and reared its ugly head.  So I backed up the information and did the Dell DataSafe Restore and Emergency Backup thing.  Big mistake.  Now the system gets to the Windows 7 boot animation and just as the four colored balls are getting ready to merge into the Windows 7 logo, the system reboots.  In safe mode, the same thing.  I've tried it three times and always the same.  Just as the balls are flying around and getting ready to merge into the Windows Logo, it reboots.  I did hit F8 during boot up and told it to stop automatic reboot on system failure and got an error code (which I didn't write down so I don't have the exactness) that directed me to a possible registry change that needed to be applied, but that's kind of hard to do when the system doesn't actually boot.  It had something to do with loading of a hard drive driver and about ATA/AHCI mode switching (if it was incorrect it would not boot up and give an UNMOUNTABLE_BOOT_VOLUME message, which the error message didn't say, but the STOP code I received pointed to as the problem).  I just find it kind of funny that everything was working fine on the computer (boot wise that is) until I did the Dell Restore thing and it doesn't boot at all now.  Of course, he never made any discs of any sort to help with this mess, so I'm stuck with a non-booting computer and a restore that caused the non-booting issue.  Any possible suggestions here?