I've been perplexed with the same problem and worked an entire day trying to get the solution below to work. I copied this from another site. Finally I was successful by using a combination of the link listed in the first paragraph and steps 1 thru 7 below. I'm really sorry I can't summarize it for you ... I just kind of picked my way through it all trying to use some common sense. Like you I tried the other methods to no avail and much to my delight this one actually worked!
Good luck!
FOR THOSE OF YOU THAT CANNOT GET THE COPY USERINIT.EXE WSAUPDATER.EXE TO WORK --> PLEASE READ THIS
OK, I read an old post from annoyances.org, way back in 2004, it is practically the only one that differs from all the others, THIS worked for me, where the copy userinit.exe wsaupdater.exe did NOT:
Article post: NOTE I am modifying the post to how it worked for ME
http://www.annoyance...xp/1096561524?s1) Use the XP disk and go into the Recovery Console
2) "We need to replace the software hive with a previous good backup."
a.) type cd system32\config enter
b.) type ren software software.old enter
This renames the current software hive to software.old
c.) type copy C:\windows\repair\software enter
It should say "1 file(s) copied"
d.) type exit
this will leave recovery console
3) Hit F8 before Windows starts to enter Safe Mode - You should hopefully be able to log in now
4) Now we need to Fix the registry
a.) Start-->Run--> type regedit, enter
b.) Select/Highlight HKEY_LOCAL_MACHINE
c.) Hit File-->Load Hive
d.) Find where you saved the software.old file (C:\windows\system32\config\software.old)
e.) Just name it test
5) THIS IS WHERE MY FIX Differs from the previous post
a.) Navigate to test\software\microsoft\windows nt\currentversion\winlogon
b.) Look for the Userinit field
c.) Mine was blank which was causing the log off loop, others had wsaupdater.exe in this key
- Double click on the ky and type C:\windows\system32\userinit.exe,
Note: if anything differs repeat step 5 with HKEY_LOCAL_MACHINE\software\microsoft\windows nt\currentversion\winlogon
6) Restart and log back into Recovery Console
7) Restore the original hive now
a.) type cd system32\config enter
b.) type del software enter
c.) type ren software.old software enter
d.) type exit enter
8) Log back into Windows normally. This worked for me and I hope you find that it also works for you! Thanks, good luck