I have a Dell Insperon 531 desktop with Windows Vista 32bit OS. What i want to know is can I upgrade to Windows 7 64bit or do I have to do a clean install? I have run a Windows 64bit test on my system and it said I was 64bit ready.
Yes, only way is to install a fresh install, basically.
you will have to do a clean install. This is what Microsoft says:
"If you're running a 32-bit version of Windows Vista, you can only upgrade to a 32-bit version of Windows 7. Similarly, if you are running a 64-bit version of Windows Vista, you can only upgrade to a 64-bit version of Windows 7. Otherwise, you'll need to use the Custom option to install Windows 7."