When troubleshooting Windows problems one of the first question to ask
is "what did you do to cause the problem?" What software or hardware
did you install or uninstall? The original poster already told us that
the problem was caused by a botched Service Pack installation, or at
least that is what he or she did right before the problem started. We
can't be 100% sure that that is the sole cause of the problem, but it's
a good place to start investigating.
Your reply that the ntldr was damaged is not only improbable it is
impossible. ntldr is the NT Loader, the starter for the operating
system, comparable to the starter in a car. Without a starter the
engine doesn't crank, it doesn't turn at all, it can't start or backfire
or do anything. Using that analogy a Windows NT operating system
without ntldr or with a damaged ntldr also doesn't "crank" at all!
Without ntldr you don't get *anything* Windows happening when the
computer boots, no Windows Splash Screen, no Windows logon screen, no
rebooting, no nothing! All you get is a black screen with a message
telling you that ntldr is missing or screwed up, the boot process barely
makes it out of the BIOS post routine before it halts.
Then we examine the notion that the problem is all of a sudden caused by
a flaky Power Supply Unit or a cracked motherboard, remotely possible
but highly improbable. First the original poster mentioned nothing
about symptoms that would be expected from these type of failures and
mentioned nothing about dropping the computer or changing hardware in
the computer, which might have resulted in damage to the motherboard.
Furthermore the kind of hardware problems that you suggested usually
cause the computer to fail the POST test and not boot at all or they
pass the POST and then under heavy usage or after heating up they
mysteriously and suddenly shutdown with no apparent warning or reason.
Of course anything is possible and what I just said is not %100 always
the way it goes but it "usually" follows these lines. The posters
problems don't quite fit in with your diagnosis. You might want to read
here to find out what happens when you boot an NT computer:
The PC Boot Process
http://dotnetjunkies.com/WebLog/unknownreference/articles/12284.aspx
Chapter 19 - What Happens When You Start Your Computer
http://www.microsoft.com/resources/...orkstation/reskit/en-us/booting.mspx?mfr=true
Some of the information in Chapter 19 is a bit dated but the basics all
still apply to Windows XP.
John
PS: My suggestion would have been to try to boot to the Recovery
Console and launch the spuninst.bat to try to remove the botched Service
Pack installation. But I wasn't sure if the outcome of that would have
fixed the problem, other steps thereafter would have taken more time and
skill to attempt. In the end the Microsoft solution is probably the
best one...