There are a lot of reasons can cause NTLDR Missing, here is just one simple example:
HP Pavilion a1357c with Windows XP Media Center 2005, when starting, it shows “NTLDR Missing”
With first repair, I found there is nothing in driver C but the only folder Windows.
F10 to recover, failed because files could not be copied after 90% of the recovery processing.
Then use CD to fresh install…