As a followup to Replacing Your Hard Drive, Harold wrote me to say:
Thanks for taking the time to send the valuable info about hard
drive. I thought I would try and explain the registry corruption,
since it was not clear.
Upon booting one morning after using the computer the afternoon
before, I got to the welcome screen and there were no user accounts
for me to click on and finish the boot process. This had happened
once before so I did what I did before. I removed the hard drive from
the computer and put it into the external usb hard drive enclosure
(one of my most useful purchases to date, which you recommended) and
got the registry file ‘Sam’ from the Repair folder that windows
creates after XP is first installed. I copied that file to the
Window/system32/config folder. (I had renamed the existing file as
sam_old.) After putting the HD back into the computer I was able to
get back into it. Windows did, however, revert back to the way it was
right after XP was installed. (no user accounts) But I was able to
get back into the PC and am still using it until it happens again or
I replace the hard drive.
Thought this might be helpful to someone else in the future. Thanks
Thanks, Harold. This very well may help another reader in the future.
The Windows Registry "sam" file, for most Windows XP computers, is found in the
C:\WINDOWS\repair folder, along with a few more backup copies of critical files.
The name of the file is sam — no extension, no capitalization, just sam. The name stands for Security Account Manager and the file contains information stored in the registry HKLM\SAM key about the Security Accounts Manager (SAM) service.
Readers might want to check this article (KB307545) at the Microsoft Knowledge Base, which discusses the sam file.
In particular, the repair procedure in KB307545 advises you to COPY the current sam file (and some other files) as backups before you do the copying that Harold did.
That way, you can at least return to the versions that you had, if the “repair” versions aren’t what you expect — your computer’s manufacturer might have created different default IDs, for example.