I can only familiar with XT. I had netbook and system board went south out
of warranty. At a local PC shop I bought pieces to assemble a desktop a
year ago, they ask to see my hologram Windows S/N sticker. After varifying
I had one he make a copy of the XT CD. Installing on the new desktop, and
new HD, the CD wanted, demanded, I enter the 5 by 5 S/N. With that it was
happy and continued installing XT. I think you have 30 days to register
each install with MS.

I don't know the terms of Win 7, check with a local HD supplier, tell them
your predicament. They should be able to supply you a CD, or copy onto a CD
you supply, Win 7. Have the agree to provide you a copy of Win 7 if you buy
an HD from them. I hope you have the Win 7 sticker with the S/N readable.

I have bought 2 netbooks, both have the S/N sticker, and a friend gave me
his old XT, it also has the sticker.

I'm curious about Win 7. Does anyone know what the MS policy on Win 7 and
the sticker/license? Is it basically the same as XT?