Aha. Tak pak asi takhle:

Recovery discs have the key built in, you don't need a key if you use the recovery disc set.
The product key used by the recovery disc set is different than the one on the COA sticker.
VLK key, used by recovery
OEM key is on the sticker. (your personal key)
You can use a "key finder" program to record the VLK key.