Quote: Originally Posted by pratnala
What do you mean by a retail version?
An OEM version is the the one supplied by computer manufacturers or you can buy an OEM version yourself - OEM stands for Original Equipment Manufacturer and this version remains with the computer it was installed on. It cannot be transferred to another computer.
A retail version is software that you buy from the Microsoft store or other reseller and it can be transferred to another computer providing it is removed from the old one first.
As Noel states, the OEM version only provides you with one DVD whilst the retail version provides with two discs: one for the 32-bit version and one for the 64-bit version. You can install one or the other, but not both, unless you have a multi-user licence.