Windows ships with two built-in licensing tools that don't require the Settings app at all: slmgr (Software Licensing Management Tool), a command-line utility, and slui (Software Licensing User Interface), which opens graphical activation dialogs. Between them you can install a key, activate, check status, and troubleshoot — useful when Settings itself is misbehaving, or you just prefer the command line.
Before You Start
- A genuine Windows product key
- Administrator access to Command Prompt or PowerShell
- An internet connection for online activation
1.Open an elevated Command Prompt
Right-click Start and choose "Terminal (Admin)" or "Command Prompt (Admin)." slmgr requires administrator rights — it fails silently or with an access-denied error otherwise.
2.Install the product key
Run: slmgr /ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX, replacing the X's with your actual key.
A dialog confirms "Product key installed successfully" — this only means the key was accepted, not that Windows is activated yet.
3.Request activation
Run: slmgr /ato
Windows contacts Microsoft's activation servers and, within a few seconds, returns a success or failure message confirming whether activation completed.
4.Alternative: use slui for a graphical dialog
If you'd rather not type the key into a command, run slui 3 to open the standard "Enter a product key" window instead — functionally identical to the Settings > Activation flow.
slui 4 opens the phone-activation wizard, used in the rare case online activation isn't available (for example, on an isolated network) and you need to activate by calling Microsoft.
Verify activation status
Run slmgr /xpr to display a one-line status: either "The machine is permanently activated" or the date/condition under which activation expires (relevant mainly for volume-license or KMS setups, not retail/OEM keys).
For full details — key channel, activation ID, license status — run slmgr /dli, or slmgr /dlv for the extended version.
Troubleshooting
| Issue | Likely Cause | Fix |
|---|---|---|
| Error 0xC004F074 — "the Software Licensing Service reported that the computer could not be activated" | No route to Microsoft's activation servers, often due to no internet or a KMS client setting left over from a corporate image. | Confirm you're online, then retry slmgr /ato. If the PC was ever on a corporate KMS network, also run slmgr /skms and slmgr /rearm to clear the leftover KMS server address. |
| "The Software Licensing Service reported that the license is not enabled" / invalid key error | The key doesn't match the installed Windows edition, or contains a typo. | Confirm the key's edition (Home, Pro, etc.) matches what's actually installed via Settings > System > About, and retype the key carefully — 0/O and 1/I are the most common mix-ups. |
| slmgr commands do nothing / "access denied" | Command Prompt wasn't opened with administrator rights. | Close the window and reopen it via "Terminal (Admin)" or "Command Prompt (Admin)" from the Start right-click menu. |
