Windows 8.1 HVM - Windows mouse pointer moves at wrong speed

[Robin Green]

After my Windows 8.1 VM updated itself today, first the Windows mouse pointer disappeared entirely, and then when I rebooted it, it stopped moving as far as the Qubes mouse pointer, so the two mouse pointers became out of sync.

The solution was to go into the Control Panel in Windows and in Mouse Settings, disable "Enhance pointer precision" (which is a bit tricky to do while the mouse isn't working properly).