Symptoms

A Windows virtual machine intermittently freezes when applications inside the virtual machine are used.

Cause

An anti-virus application scanning a virtual machine file or the folder of its location.

Resolution

Add the virtual machine file (.pvm) or the whole folder containing it to the exclusions of an anti-virus application installed on the Mac. How to find my virtual machine on the Mac?

Or uninstall an anti-virus application from the Mac.