So, believe me, I've read all the related posts on how to fix "NTLDR is missing" issues on SuperUser and this is not that question. I actually did manage to fix my problem, but I don't entirely understand why the fixed worked and its bugging me. I'm hoping someone out there can fill in the blanks for me.
Background
A friend of mine has an old HP laptop from about 2006 running Windows XP Home SP2. I was fixing some various issues, work on the general slowness of the machine and installing new antivirus software (AVG). I was on a horrible internet connection and had to cancel the AVG install partway through downloading (I did this cleanly) and rebooted.
When the computer started up again, all I got was the message
NTLDR is missing....press Ctrl-Alt-Del to Restart
I understand what that means, though how it happened in the first place based on what I was doing somewhat mystifying.
Question 1: Any idea how this error occurred in the first place?
The Needed Fix
So the fun part about this laptop is that all its external drives are kinda busted, so I had to grab an IDE-to-USB cable, pull out the laptop hard drive and hook it up to my desktop. I know that I need to replace the probably corrupt files NTLDR and NTDETECT.COM files in the root of the drive, but no matter what type of search or listing I do, I don't see them at all.
The only hidden or system file sitting in the drive root is pagefile.sys. I couldn't findboot.ini` either.
Question 2: Despite have show hidden files and show system files turned on, I could not find NTDLR, NTDETECT.COM or boot.ini anywhere. Why couldn't I see these files on the laptop's hard disk when it was mounted via USB on my desktop (I find it hard to believe they just disappeared)?
The Actual Fix
In the end, I grabbed a Windows XP install disk and just copied over NTLDR and NTDETECT.COM as well as a generic boot.ini to the root of the laptop drive. I got no file replacement prompts or anything...I just moved the files over with a simple drag and drop. When I put the hard drive back in the laptop and booted it up, it worked.
Question 3: Why in the world did this fix work? Did NTLDR just straight up get deleted somehow originally? Or was I just not looking for it properly?
I love that my problem is fixed, I hate that I don't really understand why. Anyone have any wisdom to share? Thanks much!