No boot device available; previous attempts failed at checkout 00b4

Hi, my Dell Dimension 660 (approximately 18 mos. old) would not allow me to log in yesterday - I repeatedly got the error message "User profile service failed to login / can't be loaded".

I tried accessing safe mode to address this, but did not find the "Safe Mode" that I'm used to... I did access something called the Aptio Setup Utility. I don't believe I inadvertently changed anything in it, but now receive a "No boot device available" statement upon trying to boot the computer. I also have seen the message "Previous attempts to boot have failed at checkout [00b4]" flash by a few times when trying to reboot, though not consistently.

The Dell diagnostics checks out without any problems with the motherboard, memory, or anything else. Although I initially had a CD in my CD drive, I've removed that (and have disconnected any other USB connections). Any thoughts would be greatly appreciated, as I'm at a loss,

Dave

You can boot the Win7 disk for your version available in Reinstall tutorial below, select Repair on second screen, open a Command Line and enable Hidden Administrator from WinRE. Built-in Administrator - Enable from WinRE

Now you can go into Control Panel>User Accounts and create a New Administrative-level account to set it up and see if it runs correctly. If so transfer over your files gradually while you make sure all Programs will run from it and if not reinstall them. Then delete the old profile.

If the problem is not the User Account then work through the Troubleshooting steps which apply from either link below. You'll want to check for infection, check System File integrity, possibly do a Repair Install or Reinstall which are covered from within the OS or from boot in each tutorials.

I've downloaded the registry repair program from another computer onto a flashdrive (as I can't seem to access the internet from the Dell Dimension 660 that I'm having problems with), but upon inserting the flashdrive into the USB port, the Dimension 660 doesn't automatically read it and I haven't figured out a way to get to a C: prompt, etc.

Your suggestion sounds quite promising, but I'm stumbling out of the starting gate - any suggestions?

Thanks,
Dave

What Registry Repair program??

Use Option 2 in the blue link tutorial I provided, from the Command Line which it shows how to access by clicking its own blue link.