This activation will only work if you have a SLIC ACPI table and the SLIC version is 2.1.
You need to use the OEM.XrML and slp.bat corresponding to your OEM so the SLIC and SLP match.
You should match the Edition of your Windows 7 COA.
For systems with Windows 8.1 Pro OEM and Windows 10 Pro OEM use the Windows 7 Pro OEM OEM.XrML and slp.bat.

1. Install Windows 7 using Retail Installation Media.
2. Select Correct Edition (note you will only get this option if no EI.cfg file is present).
3. Uncheck Automatically Activate Windows when I’m Online.
4. Skip Entry of the Product Key.
5. To apply OEM SLP, select your OEM from the list of folders, select your Windows 7 OEM Edition and copy the OEM folder to C:\
6. Open the OEM folder, right click slp.bat and select "run as administrator".
7. Click ok three times.
8. Go to start, right click computer and then select properties. Windows 7 should be activated. The Product ID should contain OEM-899.