Microsoft distributes Windows Server as an evaluation ISO, and converting that installation to a fully licensed one is the normal, supported route rather than a workaround. It is a single command, but the details matter.

Before you begin

Check three things. Confirm which edition your key is for — Standard or Datacenter — because you can convert up but not down. Confirm the current state with DISM /online /Get-CurrentEdition in an elevated command prompt. And take a backup or snapshot: this is a one-way change.

The conversion command

Open an elevated command prompt (right-click, Run as administrator) and run the command for your edition, substituting your own 25-character key in place of the placeholder:

For Standard:
DISM /online /Set-Edition:ServerStandard /ProductKey:XXXXX-XXXXX-XXXXX-XXXXX-XXXXX /AcceptEula

For Datacenter:
DISM /online /Set-Edition:ServerDatacenter /ProductKey:XXXXX-XXXXX-XXXXX-XXXXX-XXXXX /AcceptEula

The process takes a few minutes and requires a restart. Do not interrupt it.

Confirm afterwards

After the restart, run slmgr /dli in an elevated prompt. It reports the edition and licence status directly. You can also re-run DISM /online /Get-CurrentEdition to confirm the edition has changed.

Common problems

• “This edition cannot be upgraded” — usually a key and edition mismatch, or an installation that is already licensed rather than evaluation. Check with Get-CurrentEdition.
• Conversion succeeds but activation fails — the edition changed correctly but the machine cannot reach Microsoft. Servers are often isolated, so use telephone activation; our free Confirmation ID service covers it.
• Server Core — the same command works; you are simply running it in the only shell available.

Need a hand?

Send your order number and the exact output of the failed command — DISM error text is specific and usually tells us the cause straight away. Browse Windows Server keys.