A Windows Server evaluation runs for 180 days. slmgr /rearm resets the period, and after a restart you have another 180 days. Open the Command Prompt as Administrator:

slmgr /xpr
slmgr /dlv
slmgr /rearm
shutdown /r /t 0
  • /xpr shows when the evaluation expires.
  • /dlv shows license details, including how many rearms you have left (?Remaining Windows rearm count?).
  • /rearm resets the period. It only takes effect after the restart.

Tip: Output in the console instead of a popup

slmgr normally answers with a dialog box. Over RDP or in scripts that gets annoying. With cscript the output goes straight to the console:

cscript //nologo %windir%\system32\slmgr.vbs /dlv

How often can I rearm?

Usually up to five times. Rely on the number from slmgr /dlv, though, because it applies to your exact system. If it says 0, only a license will help.

Out of rearms: convert the evaluation to a full version

With a valid product key you can turn the evaluation into a full version without reinstalling. First check which editions you can switch to:

DISM /online /Get-CurrentEdition
DISM /online /Get-TargetEditions

Then convert, for example to Standard:

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

The server restarts afterwards, sometimes twice. The conversion does not work on a domain controller. If the evaluation has already expired and the server keeps shutting down, see My Windows license has expired. Now what?

Windows Server at Prepaid-Hoster

If you rent a Windows Server from us, it comes with an evaluation license valid for 180 days. After that you need a valid license, or you reset the period as described above.

If you set up Windows on a vServer using the automatic installation in the Cloud Manager and the Guest Agent is running, a cron job takes care of the rearm for you. You only have to restart the server afterwards. This is done on a best-effort basis without guarantee, so check the license status yourself with slmgr /xpr. Dedicated servers and installations from your own ISO do not get this automation.

License terms

The evaluation is meant for testing. Running Windows Server permanently without activating it violates Microsoft’s license terms, even if the system technically keeps running.