I was installing XP Pro on another HDD in my system and apparently I deleted what I assume to be the partition for booting my 7/64 os while yacking on the phone

This is as bad as texting, talking and driving at the same time! Should have been paying more attention...I Know.
I can see all my personal folders as well as the Windows folders in the XP "MY Computer" icon but it won't boot the HDD. It'll say "No Hard Disk Detected" or something to that effect when I'm trying to boot that particular drive.
I've tried some recovery tips but no luck yet. I'm trying Active@ Partition Recovery s/w now to see if I can get the boot partition recovered. It's still scanning very slooooowly.
Some help please
Thx