Thanks natakuc4! I followed your instructions but every time I type the product code that is on the sticker on the bottom of my XPS (5 times 5 characters) I get invalid product code. It is totally driving me crazy. I know for 100% it is the correct code. Tried everything, but no luck.  When windows 7 was first installed SP1 was not out yet. Could this be the problem? In this case I need windows 7 without SP1. Would be crazy. Otherwise I need to request for the original DVD via Dell-Support. 
I have recently had to install a completely new HD (SDD in this case) and now I am looking for the Windows 7 Home Premium 64-bit discs to reinstall my OS. I have tried the DVD (english) from the US site, but my product key does not work on that disc. Does anybody know where I can download the original DVD (dutch) that had to come with my system (but didn't). I have paid for a license. Thanks in advance for you answer.
Need Windows 7 Home Premium 64-BIT dutch reinstall discs for complete new 
install. Where can I find these?