Is your Surface Pro pen not working after a Window update? This solution has works for me.
Whenever I get a Windows 10 update, the new November 2017 Creators update, for example, I lose the use of the stylus for my Surface Pro. The Bluetooth says it's connected, but it does not work. This is the solution I found online that has worked every time. My only problem with the Surface Pro 4 (it is fantastic for drawing with Clip Studio Paint) are the random Windows updates and the fact that it kills the pen every time.
Here's the solution:
1. Click and hold the power button for 30 seconds. The Surface should shut down.
2. Hold the Power button and the Volume Up button together for 15 seconds. There might be a flash on the screen of the "Surface" logo for a second.
After this, power back on and everything should work fine. If you're reading this post and having this problem, I hope this solution works out for you!