registry editing has been disable by your administrator

Enable Registry Editor using the Group Policy Editor

1. Click on Start. Go to Run. Alternatively, use Windows key+R keyboard shortcut.
2. Type gpedit.msc and press Enter.
3. Navigate to User Configuration/ Administrative Templates / System.
4. In the work area, double click on "Prevent Access to registry editing tools".
5. In the popup window, encircle Disabled and click on OK.
6. Normally, Registry Editor will be immediately accessible. If it is not, restart your PC.

https://www.tweakandtrick.com/2011/04/enable-regedit-registry-editor.html?m=1