Hello, I am a student and I bought a windows 7 with MSDNAA license from Ebay, The seller sent me a copied version of windows 7 and the product key, claiming that the key is legal, not activated. The question is: how can I make sure that this is indeed a legal key ? Thanks

It's an extremely high probablity it's illegal! Any genuine Windows disc will come with a halogram and a license label/sticker. Check Windows Genuine info @ http://www.microsoft.com/genuine/ You should report the seller to eBay for selling counterfeit products.