Windows 10 guest hanging

[Hank Knox]

I have been running Windows 10 as a guest in a QEMU/KVM VM under Debian 
testing for several years now with no problems. After a recent set of 
qemu updates from Debian early this last week, Windows freezes after a 
few minutes of use: I get a spinning 'busy' cursor and the UI stops 
responding. The only thing to do is forcefully close the instance. I 
don't know where to begin to sort out where the issue is: Something with 
QEMU? A WIndows problem that requires a reset/reinstall? Some other 
Debian library problem? Any suggestions would be welcome.

Thanks in advance,
--
Hank Knox, FRSC
Schulich School of Music of
McGill University (retired)
Montreal, QC