A single background process — PAD.BridgeToUIAutomation2.exe from Microsoft Power Automate Desktop — was causing system-wide input freezes, mouse stuttering, keyboard input loss, and audio dropouts on a high-end workstation (i9-14900K, RTX 4090, 96 GB RAM, 4K 120Hz). The root cause: Power Automate's UI Automation bridge subscribes to global accessibility events, which forces every windowed application to generate cross-process callbacks on every repaint. This created a cascading DWM composition stall that affected the entire system. Disabling Power Automate from startup instantly resolved all symptoms.
- CPU: Intel Core i9-14900K (32 logical processors)
- GPU: NVIDIA GeForce RTX 4090 24 GB