A quick tech-tip on how to resolve the issue whereby the Windows Phone 8.x or 10.x emulators stall upon launch at the initial “Windows Phone OS is starting…” loading screen.

The root cause is usually related to invalid or corrupted Hyper-V networking configuration and rather than waste time troubleshooting, I recommend just resetting the emulators back to factory defaults:

Finally run xdecleanup.exe as administrator for every version of XDE installed

# C:\progra~2\Microsoft XDE\8.0\XdeCleanup.exe
# C:\progra~2\Microsoft XDE\8.1\XdeCleanup.exe
# C:\progra~2\Microsoft XDE\10.0.10586.0\XdeCleanup.exe