Windows 7 WILL NOT boot.

[P373R]

hi.
i currently have installed one 500GB WD
and one 80GB WD
both sata.

however both of them had windows 7 beta installed on them.
[dont ask, long story]
now. i went to try and format the 80GB. and said it could not be done.
so i did it the only way other way i know how/.

windows 7 install disk.
the format appeared to go ok. [couldnt tell, as win7 built in fast formatter shows no work done]
but now....my 500GB refuses to load win7 at all.
i get this error.

Bootmgr not found
press Crtl+Alt+Delete to restart

any help?

 

[Bodaggit23]

Boot from the disc again and go into the install.

This time, select to "Repair an existing OS" or such.

This will repair the boot manager.