Q: PDF Studio seems frozen and no keys or mouse clicks seem to have any action.

A: If PDF Studio does not seem to respond anymore, you can force close / kill the process by following the steps below:
In Windows:

  1. Press Ctrl + Shift + Esc to open Windows Task Manager
  2. Click on the “Processes” tab at the top
  3. Click on the header “Image Name” to order processes alphabetically
  4. Select pdfstudio9.exe in the list of processes
  5. Click “End Process”
Click on pdfstudio9.exe and on "End Process" to kill PDF Studio.
Click on pdfstudioX.exe and on “End Process” to kill PDF Studio X (where X is your version of PDF Studio).