Perhaps some good legal news for you! found it on google
http://www.microsoft.com/licensing/downloads/reimaging.doc
What we found out is if you have an Volume license
agreement with Microsoft, either open or select (I
believe there are others) you can use your volumn license
media and key to create the RIS image and the OEM license
will keep you legal. So as long as you have an OEM
license for every pc you can use the volumn media to
create a RIS image that you can load on all your OEM pcs.
Since I work for State Government our state has an open
license agreement with Microsoft and all we had to do is
join the agreement. For others I don't know how you get
an agreement with Microsoft. I hope this information
helps if you have any questions feel free to email me at