With this PowerShell script, you can edit your OEM information!
This script modifies registry keys. Path : HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\OEMInformation
If you wish to remove those modifications, just press Enter key when script is asking input for you. This will skip it and remove OEM information or you can do this manually. Head to HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\OEMInformation and remove this key!