If your touchscreen or pen suddenly stopped responding, the fix is often far less dramatic than you fear: the Touch Keyboard and Handwriting Panel Service (a.k.a. Tablet PC Input Service) may simply be disabled or set to the wrong startup type, and re-enabling it typically restores touch, handwriting, and on-screen keyboard functionality within minutes. This feature-first guide explains exactly what the service does, shows multiple safe ways to re-enable it (Services GUI, PowerShell, and...