Parallels Toolbox appears to have trashed Windows

I recently upgraded to Parallels 12 and everything appeared normal. I then recently installed Parallel Toolbox and Windows appears to be trashed. The screen in black and I can't open any programs. What can I do??

 

Hello,
Parallels Toolbox is independent application and can't affect Parallels Desktop behavior.

Try
step 1: quit from all running Parallels Toolbox tools
step 2: quit from Parallels Toolbox
step 3: check your issue with Parallels Desktop. Does the problem still exist?

 

I have removed Parallel Toolbox form the computer and the problem persists. Black screen and can't open progress in Windows 10.

 

In this case I would recommend you to contact with Parallels Desktop support service