NTLDR Problem!!! Plz Help

Hey If I could get a hand with this I would really appreciate it. I have XP Por SP-! running on my system and everything runs fine until I try to add my 40GB Hard Drive as a slave. Then when I boot it gives me the NTLDR is missing hit CTRL+ALT+DEL to restart. I cant figure It out I have tried everything and the 40Gig is in XP format. Plz Help me out.


Sys Specs
AMD 1150 Proc
Radeon 7200 64DDR Vid
512 DDR Ram
Sound Blaster 5.1 Platinum Sound