Windows has 3 types of licensing
- OEM
- RETAIL
- VOLUME
OEM is original equipment manufacturer which is provided by our machine manufacturer like Dell, HP etc. preinstalled on laptop.
RETAIL is the one which is purchased, from Microsoft via any seller and usually comes within CD with key. Though it can be downloaded officially from Microsoft but the ‘key’ is key here.
VOLUME is for corporate users having licensing agreement for their devices in their network.
You can check the type of license via Windows SOFTWARE LICENSE MANAGER (SLMgr)
to (display license information):
slmgr/dli
for more information
slmgr/dlv
OEM does not provide us the product key, instead it is written in the bios by the laptop manufacturer. So if we do a clean install of windows, key will be automatically detected by windows and it won’t ask for the key. But the support isn’t provided by the Microsoft rather you need to contact manufacturer itself. OEM windows are permanently activated. OEM’s are lesser in price than Retail and seller asks us whether we want laptop with genuine windows or just DOS.
RETAIL provide us the product key which will be asked during the installation of windows hence it is easier to move the licensed version of windows in another machine just by entering the product key. Its support is provided by Microsoft. They have a expiration date for 1 year, 3 year etc and are pricier than OEM you can check price at Amazon.
VOLUME licensing has all the machines in a network activated under the Key Management service (KMS). The Key Management Service (KMS) is an activation service that is used by organizations to activate systems within their own network and thus no need for individual computers to connect to Microsoft for product activation. How KMS works is that every computer in the network needs to connect to a Remote KMS Server which assigns it a volume license usually for 6 months.
After using slmgr/dli Look at the description, it shows RETAIL. An OEM windows will show OEM and a volume one will show VOLUME in description.
To check expiration period of windows:
slmgr/xpr