Pulled right from microsofts site. How to repair/replace a damaged/missing boot.ini file... Heres a link to the whole article.
I completed the How to repair/replace a damaged/missing boot.ini file but the computer still had the error. =/
Well the only other thing I can think of for you to do, is to take out your harddrive and connect it to a PC with the exact same OS/Service Pack as yours with the same partition setup as yours and to copy the boot.ini file from the working pc to the non-working pc. I have never done this and am not sure if it will work but what have you got to lose right?
Possibly, I'm not sure what the repair process does, but I can imagine if there isn't one there at all there could be issues.