Open one of the Office applications, for example Word and close initial window that is asking for serial key.
Open “cmd” as Administrator and run following commands (separated with #): # cd /d %ProgramFiles%\Microsoft Office\Office16 # for /f %x in (‘dir /b ..\root\Licenses16\ProPlus2021VL_KMS*.xrm-ms’) do cscript ospp.vbs /inslic:”..\root\Licenses16\%x” # cscript ospp.vbs /setprt:1688 # cscript ospp.vbs /unpkey:6F7TH >nul # cscript ospp.vbs /inpkey:FXYTK-NJJ8C-GB6DW-3DYQT-6F7TH # cscript ospp.vbs /sethst:<IP OR FQDN OF YOUR KMS SERVER> # cscript ospp.vbs /act