License Transferable?

[cmnpgm]

I purchased a block of 50 licenses for my company several years ago. I have over the years used probably 40 of them (small company).
I am in the process of slowly updating machines/OS to Win 7 or Win 8. In the process, the old machines are wiped.
Are the licenses transferable, or would I require a new block of licenses?

[tzuk]

Please send me an email with your order details.