Windows 10 IoT LTSC: UWF enabled causes massive boot delay when NO USB mouse is connected

Environment OS: Windows 10 IoT Enterprise LTSC 2021 (build 19044.x) UWF: Enabled, protecting C: only Overlay: RAM overlay , max 1024 MB , persistent = OFF Fast Startup: Disabled (same state for all tests) Problem summary I have a Windows image using Unified Write Filter (UWF) on C: . Boot time behavior changes drastically depending on whether a USB mouse is present at power-on: UWF OFF: boots ~ 1:40 (mouse present or not) UWF ON + USB mouse plugged in: boots ~ 1:40 UWF ON + NO USB mouse plugged in: boots anywhere from ~ 4:25-30:00 (slow/hangs at Windows logo/spinner stage, then eventually reac

Question by Jake Henry on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.