Cant activate, Reinstall of win7, worn off product key

I just did a clean install of windows seven using my OEM disk purchased a few years ago for this laptop. The sticker with the product key, has been damaged and I cannot read 6 characters. The laptop came from HP with vista, win7 was installed on a new hard drive using the same OEM disk. I am unable to activate windows 7. Is there any way to retrieve the activation code? or possibly a replacement? Any help would be appreciated.

UPDATE: Solved
I called Microsoft at 1800-642-7676 and explained the situation. They kindly generated a new key free of charge after approval from their supervisor.

Hi,

Try to use a bright light and magnifying glass to decipher the letters. Do you still have the recovery disks for the laptop? If you do, you could try a recovery from that, and we can take it from there.

If you are unable to do that, then the only option left is purchase a retail version of Windows 7.

Regards,
Golden

Wow. So I already did try using a bright light to decipher the characters, but came up empty. I tried to load the recovery disk to see if it was from the vista or win7 version because I couldn't remember if I made them. They are from the vista version. Apparently this was a horrible idea because: Now the computer will not boot (even from a disk). It just says "BOOTMGR is missing press Ctrl+Alt+Del to restart".

EDIT: well it seems to boot off the OEM disk now, I am just going to avoid this whole activation ordeal and put a copy of win8 or linux on it. Thank you for the help.

UPDATE: Solved

I called Microsoft at 1800-642-7676 and explained the situation. They kindly generated a new key free of charge after approval from their supervisor.