3 user accts all with user profile service fail

Hi all. I have a rebuilt HP, system model HP compaq dc5750 sm. form factor, with Vista business 64 bit, 1 80GB and 1 2TB HDD's and a 500GB external HDD that I took out of my slimline when the power died. AMD Athlon 64x2 Dual Core proc. 3800+ 2.)GHz, 4 GB ram standard cd-rom,ATI Radeon XPress 1150 and ATI Radeon Xpress secondary. This is only for quick specs.

Right now all 3 user accts have the same "user profile service service failed the logon" message. I've read everything I could find here and at Microsoft's support forum. First of all I tried booting in everyway possible from f8 and the only way I can logon in any way,shape or form is in safemode with command prompt. I used my 2nd admin acct. that I have set up to use for problems only. Great, fine. I'm finally on. I went to regedit and followed the path:HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList and all of our user/profiles in the S-1-5 lines have bak at the end. In control panel I can only access the user acct. I logged on with (in safe mode) and it will not let me create a new user acct., which I could then use to log on as a working acct. and fix our "bad" accts. I also tried enabling the built in administrator account with command prompt and my pc hated that idea too. I also tried doing system restore in the safemode I was in,that's the only way I really can actually(duh to me). That didn't help either, and I can't use the recovery cd's I have because the installation program says I have to have a back up copy created. That's inaccessable at the moment. More info about that below.
2 of the user accts are admin and 1 is a standard. As I said above one of the administrator accts is supposed to be for problems only, as my son used to have a bad habit of not scanning his dl's for viruses or not remembering what the pc error message was! I hate when he says "I don't know".

From other things I've been reading about this horrid problem,I think I know why this happened. I think I can't boot from the HDD I'm talking about now because I copied our user files to the external HDD when I finally got around to setting it up . After awhile I wasn't able to boot from the internal HDD because of the above prob., so I've been booting from the external HDD. That's probably not a good thing? But now my external won't boot because of the BSOD, but that's for another post. I just want one of my drives working so my son can have his pc back. This is driving me nuts because I have 3HDDs and can't use any.
Help!! Thanks in advance.