By the way, I am not into PC troubleshooting as my day job (and I am not much knowledgeable with OS problems either). However, I do learn a little from time to time.
So, I got a call for help where somebody close was getting an "NTLDR is missing" error on booting his Windows XP machine. Fortunately, I had downloaded (and used) Ultimate Boot CD some time earlier. I knew this would be indispensable.
When you boot with UBCD, it provides you with lots and lots of tools. Knowing the right tool for the job takes some time.
A quick search on the Internet revealed that the three files required in the first partition for booting up a Windows XP machine include
With some effort, I found out "Avira NTFS4DOS Personal" in UBCD allows you to write to NTFS. I put in a Windows XP setup CD and copied ntdetect.com and ntldr from i386 folder of the setup CD to the root of the NTFS partition. I had to manually create boot.ini (contents copied below):
And it worked! Thanks to UBCD!
Note to self: considering that almost everyone in Pakistan uses Windows as their OS, I should give UBCD for Windows a try.