no operating sys message

Hi I recently got a Dell Latitude XPi A-Series and it has no floppy or cd drive. LIke the last poster I agree that "You're guide is great and should most definately work", but I to have run into a "Missing Operating System" error when I put the hard drive back into the laptop.

Everytime i put it back in the laptop, I always get the "Missing Operating System" error. Any ideas how to get around this little problem? Thanks in advance.

Madtown(girl)