slmgr /dlv Confirm the "Product Type" shows "Retail" or "Volume" (not "Eval") and that licensing is active.

DISM /online /Set-Edition:ServerStandard /ProductKey:WC2BQ-8NRM3-FDDYY-2BFGV-KHKQY /AcceptEula Once the command succeeds, reboot:

slmgr /ipk YOUR-NEW-PRODUCT-KEY slmgr /ato Run:

Execute the conversion command:

DISM /online /Set-Edition:ServerStandard /ProductKey:XXXXX-XXXXX-XXXXX-XXXXX-XXXXX /AcceptEula Replace XXXXX-XXXXX-XXXXX-XXXXX-XXXXX with a valid Standard edition product key (Retail or MAK). A generic KMS client key will not work for this retail conversion. If you do not have a retail key, you must use the Volume/LTSC method (Step 3b).

shutdown /r /t 0 After rebooting, open Command Prompt (Admin) and set your KMS server or enter a new key: