The latest update of Windows 10 (November 2019) includes a feature that allows you to use a pen as a mouse in Settings. If you installed a regkey, you’ll have to manually install the update and turn the feature back on in Settings. Here's how you get the latest update and turn on the feature in Settings.
Manually install the Windows 10 November 2019 Update
When the Windows 10 November 2019 Update is ready for your device, it will be available to download from the Windows Update page in Settings.
If you want to install the update now, select Start > Settings > Update & Security > Windows Update , and then select Check for updates. If updates are available, install them.
If the November Update isn't offered automatically through Check for updates, you can get it manually through the Update Assistant.
Turn on pen feature after update
- Select Start and go to Settings
- Choose Devices and go to Pen & Windows Ink
- Select Let me use my pen as a mouse in some desktop apps
Now you can start using your pen as a mouse.