Hi bluuto,
I am not certain what would have caused the icon to disappear from your toolbar, but I would first recommend following these steps to try and bring it back.
1. Right-click on a empty space on the Windows toolbar
2. Click the Toolbars option
3. Select the PC-Doctor Toolbox for Windows option
Those instructions should bring back the Toolbox toolbar, and can also be used should you feel the need to remove it from the Windows toolbar. Also, our software doesn't create a desktop shortcut by default, but a key combination that I have found helpful on Windows 8 systems is to press the Windows Flag key and the letter 'S'. The key combo brings up the search bar, and if you start by typing the name of the program your looking for(like PC-Doctor), it makes it really easy to launch without going back to the "Start" menu.
Please let me know if you have any questions, or if this doesn't bring back the icon.
Thanks,
Kris