# Click Start, and then click Run.
# In the Open box, type winver.exe, and then click OK. The version number is displayed
To determine whether you have an OEM installation of Windows, follow these steps:
1. Click Start, and then click Control Panel.
2. Click Performance and Maintenance, and then click System.
3. Click the General tab.
4. Locate the number that is displayed under Registered to.
This number typically contains 20 digits. If digits 6, 7, and 8 contain the letters "OEM", you have an OEM installation of Windows.
For example, the following sample Product ID number indicates an OEM installation:
12345-OEM-6789098-76543