I have a legally purchased CD key for Windows 7 Home Premium 32 bit from a few years ago. After discovering that CD keys work for both 32 and 64 bit versions of Windows, I'd like to download a 64 bit version of Windows. Unfortunately, the CD key only came with a 32 bit disk.
Is there any place I can legally download a Windows 7 64 bit? Will the key work for any version of Windows, or just home premium?