How to stop an unstoppable windows 7 service?

Many security software installs a special driver that intercepts any changes to its services and processes.

However, the driver is normally not loaded in Safe Mode, so you can disable the service there. If the service is still started after reboot, you may want to find and disable the driver in Device Manager. This kind of driver is normally under the "Non-plug and play drivers" section which is viewable by selecting "Show hidden devices" from the View menu. The name of the driver is normally well-known for each provider.

What about opening regedit.exe and go to

HKLM\SYSTEM\CurrentControlSet\services\[service name]

Than change the service to disable (I think you can do that by changing the "Start" value to 4).

The valid service Start types are:

• SERVICE_BOOT_START (0): A device driver started by the system loader. This value is valid only for driver services.
• SERVICE_SYSTEM_START (1): A device driver started by the IoInitSystem function. This value is valid only for driver services.
• SERVICE_AUTO_START (2): A service started automatically by the service control manager during system startup. For more information, see Automatically Starting Services.
• SERVICE_DEMAND_START (3): A service started by the service control manager when a process calls the StartService function. For more information, see Starting Services on Demand.
• SERVICE_DISABLED (4): A service that cannot be started. Attempts to start the service result in the error code ERROR_SERVICE_DISABLED.

Use taskkill command followed by the service's process ID. This will kill the service.

Have you tried opening Services.msc as an administrator or running an elevated command prompt? This should give you the required permissions to stop the task.

Some services do not accept SERVICE_ACCEPT_STOP messages, by the time it was developed. And that is hard coded into the executable. Period. A workaround would be not to have it started, and as you cannot change its properties, forcibly do the following:

1. Boot into safe mode (Windows 10 users might need msconfig > boot > safe boot)
2. Regedit into HKLM > System > ControlSet001 > Services
3. Locate your service entry
4. Change 'Start' key to 3 (manual startup) or 4 (disabled)

If you cannot change the entry, right-click on your service name on the left pane, select 'Permissions', check that 'Everyone' has full access and try step 4 again.

Don't forget to disable safe boot from msconfig again, and reboot !