Originally Posted by nekrosoft13
but there is a simple workaround. Buy what ever version of Win7 you want. Install that version on your PC, clean install. When installer ask for CD-Key, don't enter it, on next screen choose the correct version. When installer is done, insert the DVD again and select upgrade. Then enter your CD-Key, and do the install process again.
That is the only way.
Are you positive this works and how do you know it works like that for Win 7? I believe that's how it worked for Vista but it may have changed with the Windows 7.
Edit: I did find this link which supports wht you said