If it was a Retail copy and you have proof of the purchase:
How to Replace Lost, Broken, or Missing Microsoft Software or Hardware http://support.microsoft.com/?kbid=326246
If it was an OEM license, you may be out of luck - contact those you
purchased it from.
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.