How to Extend the Windows Server Evaluation Period Using slmgr
Extend your Windows Server evaluation from 180 days to approximately 3 years using the slmgr rearm command. Covers status checking, rearm execution, verification, and license conversion.
- Difficulty
- Beginner
- Time required
- 5-10 minutes
- Steps
- 5
- Platform
- Windows Server
Table of contents
Quick Answer
Go to the stepsRun slmgr /rearm in an elevated prompt, restart, verify with slmgr /dlv. Up to 6 times.
- Open CMD as Administrator.
- Run slmgr /dlv to check status.
- Run slmgr /rearm to reset.
- Restart the server.
- Run slmgr /dlv to verify.
slmgr /rearmExpected result: 180-day period resets. Rearm count decreases by 1.
Key takeaways
- How to check evaluation time, extend the trial with slmgr rearm, verify, and convert to a full edition.
- Without extension, the server shuts down hourly after 180 days. Rearm gives up to 3 years for labs and training.
- Run slmgr /rearm close to expiration. Track usage and plan licensing before reaching 0.
Introduction
Windows Server evaluation editions give full access for 180 days. After that, hourly shutdowns begin. The slmgr /rearm command resets the counter.
You can rearm up to 6 times per installation, giving approximately 1,080 days (about 3 years). Per Petri.com testing, this is the standard limit. The rearm does not affect installed applications or configuration.
This tutorial covers checking status, executing the rearm, verifying, and converting to a full license.
Who this is for: IT admins and students running Windows Server evaluation editions.
Before you start
- Access
- Local administrator access.
- Required roles
- Local administrator
- Required licenses
- Windows Server Evaluation (free)
- Environment
- Windows Server 2016, 2019, 2022, or 2025 evaluation edition.
- Vendor
- Microsoft
- Administrator permissions required
Under a minute plus a restart.
Warning: Evaluation editions are for testing only
Evaluation editions are for testing, training, and development only per Microsoft license terms.
Note: Time your rearm carefully
Each rearm is permanent. Wait until 10-15 days remain before rearming.
1Check current evaluation status
Check remaining evaluation time.
Open CMD as Administrator. Run slmgr /dlv. Look for Timebased activation expiration and Remaining Windows rearm count (max 6).
slmgr /dlvExpected result: Shows remaining days and rearm count.
Note
If rearm count is 0, you cannot extend. Purchase a license or reinstall.
2Execute the rearm command
Reset the 180-day timer.
Run slmgr /rearm. A dialog confirms success. Internet may be required per Microsoft Q&A.
slmgr /rearmExpected result: Success dialog. Rearm count decreases by 1.
Note
Each execution uses one rearm cycle. Wait until 10-15 days remain.
3Restart the server
Apply rearm changes.
Restart the server with shutdown /r /t 0.
shutdown /r /t 0Expected result: Server restarts with fresh 180-day countdown.
4Verify the extension
Confirm the reset.
Run slmgr /dlv again. Verify expiration is about 180 days from today and rearm count decreased by 1.
slmgr /dlvExpected result: About 180 days remaining. Rearm count decreased by 1.
Note
Set a reminder for 170 days from now to avoid Notification mode.
5Convert to full license (when ready)
Convert to full license when ready.
Check editions: DISM /online /Get-TargetEditions. Convert with a valid product key and restart. Domain Controllers may need demotion first.
DISM /online /Get-TargetEditionsExpected result: Server converts to full edition.
Note
Take a full backup before converting.
How to Confirm the Extension Worked
Verify fix
Desktop watermark should show 180-day countdown. Run slmgr /xpr for quick confirmation.
When all 6 rearms are exhausted, the server enters Notification mode with hourly shutdowns.
Normal result: 180-day countdown visible. Rearm count decreased by 1.
Abnormal result: If expiration did not change, rearm may have failed.
Successful
180 days remaining
Extension worked.
Exhausted
Rearm count: 0
No more extensions.
Notification mode
Hourly shutdowns
Apply license now.
Troubleshooting
Error 0xC004D307
Warning
Cause: All 6 rearm cycles used.
Purchase a license or reinstall.
Network error during rearm
Warning
Cause: Internet may be required.
Connect the server to the internet and retry.
Hourly shutdowns
Critical
Cause: Evaluation expired with no rearms left.
If rearms remain, run slmgr /rearm immediately. Otherwise apply a license.
DISM fails on Domain Controller
Warning
Cause: In-place conversion not supported on DCs.
Demote the DC first, convert, then re-promote.
Frequently asked questions
How many times can I extend the evaluation?
Up to 6 times. Each gives 180 days, totaling about 1,080 days. After all 6, the server shuts down hourly.
Does slmgr rearm work offline?
It depends on the version. Per Microsoft Q&A, internet may be required for validation.
Can I convert evaluation to full without reinstalling?
Yes. Use DISM /online /Set-Edition with a valid product key. Data is preserved. DCs may need demotion first.
What happens when all rearms are used?
Notification mode activates: watermark appears, hourly shutdowns begin.
Can evaluation editions be used in production?
No. Per Microsoft license terms, evaluation editions are for testing and demonstration only.
Conclusion
Check with slmgr /dlv, run slmgr /rearm, restart, verify. Up to 6 rearms for about 3 years. Convert with DISM when ready.
Run slmgr /rearm close to expiration. Track usage and plan licensing before reaching 0.
slmgr /rearm then restart then slmgr /dlvSources3
