After an hour on phone support where they basically removed and installed Parallels tools twice, I thought I would try my luck here. Here is the situation. Two month new MacBook Pro running Sierra 10.12.6 with updated Windows 10 Pro 64 bit installed (but failed pre-creator edition version) - started being very unresponsive, especially when clicking on start or the taskbar. It would take up to 30 seconds for it to open. Sometimes reverts to normal, but usually it's unusable in this state. The desktop also "refreshes" several times. Everything blinks and then comes back. Things I've done (none have worked): After running the DSIM to try to repair, created an entirely new VM for Windows 10, starting from scratch. Removed and reinstalled tools - changed resources (doubling from 4 to 8gb mem, 2 to 4 cores). Deleted Parallels completely and purchased the corporate version for this laptop, pointed it to the new VM I created. Still not working right. Changed small things like syncing time, turned off shared desktop, etc. Any help or suggestions would be greatly appreciated!