Don't bother downloading those Window 7 files from Rapid Share. Those keys will be (if not already) blacklisted and you'll end up with a disable Windows OS later down the road. Thousands of people have already used that Enterprise product key. Microsoft is aware.
I was going to go that route but later found out that I can just pay $261 for a year subscription to TechNet and not only get access to Windows RTM but you'll be able to download all the other MS products, like Office, Server, Exchange, etc. Plus you'll have full access to the TechNet library. This option is WAY better than paying for a single license to use one product for about the same price, plus you'll have the satisfaction of knowing it's legal.