Retail enables you to change any part of the system including motherboard without breaking any rules.
You can only run one instance at any one time.
Oem is tied to the board it was originaly installed on, but you can upgrade any other component bar the motherboard.
You can only run one instance at any one time.
Oem is tied to the board it was originaly installed on, but you can upgrade any other component bar the motherboard.