[TriLUG] Win7 & virtual machines

[M. R.]

I have Win7 and Ubuntu dual booting.

I would like to have Win7 as a virtual machine within Ubuntu.

Do I need to buy a separate Win7 (Professional) for each VM I want to 
have it as a guest?

Can I install it from the software partition (backup/source, not the 
active "C:\" drive) that comes on the laptop in question?

Thanks.