Using unauthorized activation tools (Office Crack, KMS, MAS, KMSpico, KMS_VL_ALL, AAct, Re-Loader and the like) can alter the Microsoft Office licensing mechanism, causing errors when installing or activating Microsoft 365.
To keep Microsoft 365 running reliably and licensed correctly, complete all of the steps below.
Step 1. Uninstall the existing Microsoft Office
We recommend using Microsoft's official uninstall tool (Microsoft Support and Recovery Assistant – SaRA).
The tool will:
- Completely uninstall Microsoft Office.
- Remove any remaining installation components.
- Fixes cases where removal via Control Panel fails.
When finished, restart the computer.
Step 2. Remove unauthorized activation tools
If the machine has ever used any of the tools below, remove them completely:
- Microsoft Activation Scripts (MAS)
- KMSpico
- KMSAuto
- KMS_VL_ALL
- AAct
- Re-Loader
- Office Tool Plus (if used to convert licenses or activate products without authorization)
Also delete:
- The installation folder.
- Shortcuts on the desktop.
- The downloaded ISO or compressed file.
Step 3. Check Scheduled Tasks
Open Command Prompt as Administrator and run:
schtasks /query | findstr /i kms
schtasks /query | findstr /i office
schtasks /query | findstr /i activation
If the following tasks appear:
- AutoKMS
- KMS
- Office Activation
- Office KMS
- MAS
Delete it with:
schtasks /delete /tn "Tên Task" /f
Step 4. Check Windows Services
Check for suspicious services:
sc query type= service | findstr /i kms
If you find services such as:
- AutoKMS
- KMSELDI
- KMS Service
Action:
sc stop TenService
sc delete TenService
Step 5. Remove leftover Office licenses
Open Command Prompt as Administrator.
Office 64-bit:
cd "C:\Program Files\Microsoft Office\Office16"
Office 32-bit:
cd "C:\Program Files (x86)\Microsoft Office\Office16"
Check the license status:
cscript ospp.vbs /dstatus
If this appears:
- VOLUME_KMSCLIENT
- KMS Client
- KMS Host
Remove each product key:
cscript ospp.vbs /unpkey:XXXXX
(XXXXX is the last 5 characters of the product key shown.)
Step 6. Remove KMS server configuration
If Office is using a KMS server, run:
cscript ospp.vbs /remhst
If needed, reset to the default port:
cscript ospp.vbs /setprt:1688
Step 7. Delete remaining folders
If it still exists, delete:
C:\Program Files\Microsoft Office
C:\Program Files\Common Files\Microsoft Shared\Office*
C:\ProgramData\Microsoft\Office
%LocalAppData%\Microsoft\Office
%AppData%\Microsoft\Office
Step 8. Check the Registry
Open Registry Editor and check:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office
HKEY_CURRENT_USER\Software\Microsoft\Office
If all that remains is data from the removed Office installation, or configuration created by unauthorized activation tools, you can delete it once you have backed up the registry.
Step 9. Delete any leftover activation files
Find and delete if it still exists:
- MAS_AIO.cmd
- Activate.cmd
- AutoKMS.exe
- KMSELDI.exe
- KMS.cmd
Also check the Downloads and Desktop folders and any other storage locations.
Step 10. Restart the machine
Restart Windows to complete the cleanup.
Check whether the system is clean
After uninstalling Office, run:
cscript "%ProgramFiles%\Microsoft Office\Office16\OSPP.VBS" /dstatus
If Office has been fully removed, the system will no longer have the OSPP.VBS file or any Office license.
After installing Microsoft 365, run the command above again.
If the result shows:
- LICENSE STATUS: LICENSED
- No more VOLUME_KMSCLIENT
- No KMS host remains
- No longer in Remaining Grace
then Microsoft 365 is properly activated.
Install Microsoft 365
Once the system is clean:
- Restart the computer.
- Sign in with a Microsoft account that holds a Microsoft 365 license.
- Download the Microsoft 365 installer from the Microsoft account portal or Microsoft's official site.
- Install.
- Open Word or Excel and sign in to complete activation.
Note
- Do not reuse unauthorized activation tools after installing Microsoft 365.
- Use only a valid Microsoft 365 license issued through a Microsoft account.
- If activation errors persist, use the Microsoft Support and Recovery Assistant (SaRA) to remove Office completely before reinstalling.
Cleaning the system thoroughly before installing Microsoft 365 avoids licensing conflicts and ensures Office runs reliably, receives all security updates and is covered by official Microsoft support.
