Product Key Recovery

I have an E-Machine

400MHZ processor (celeron)
32 MB ram
4.3GB disk
3D AGP graphics

With a formated hard drive,and a recovery disk,
but no product key.

Is there any way to recover the product key from the recovery disk?

I would really like to get this system up and running for my 7 year old boy to play his games on .

Can anybody help me?