I recently upgraded to Parallels 12 Desktop ver 12.0.1 41296. After the update of Parallels 12 my Win 10 virtual machine is extremely slow to startup???? No changes were made to the Win 10 installation before the update of P12 I could boot the Win 10 VM in less that a minute. Now it takes ~3-5 minutes to fully boot up and still the response time is horrible.
Since this post I ran the MS Windows Recovery Tool and now the Win 10 VM is now performing as well as before the P12 update??? Go figure???