I've just got a few questions about Windows OS's.
What is the difference between retail, upgrade versions, and OEM? I know OEM is cheaper, but why? What is it?
Also, if I were to get the upgrade version of Windows 7 from XP, how many times could I install it? I've had several problems with my computer and I've reinstalled XP many, many times. Is there a specific version that allows me to do that? Is that the OEM version?
Or, if I get the upgrade version of Win 7, will I be able to install it only 5 (whatever the number is) times? What version would I need to be able to install it more than that?
Is it possible at all to have an OS on two different machines?