Step by step instructions (built on Windows 7, so XP may be slightly different)
Right click on your Windows desktop and select New>Text Document
Rename the document to Kill_Freelancer.bat If this works correctly, you'll get a warning about changing the file extension. Select Yes. The icon will change to a pair of gears. If you don't get this, respond here, and I will post about how to display known extensions.
Right click the icon and select Edit. This will open a Notepad window.
Paste this into the Notepad window:
c:\windows\system32\taskkill.exe /im freelancer.exe /f
Click the Red X, and Save the changes.
Right click the icon, and select Send to > Dekstop (Create Shortcut) Sounds odd, but you cannot create a hotkey on the batch file
On the just created Shortcut, Right click and select Properties
Select the Shortcut tab, Go to the Shortcut key data field and press a button you want to use to run the program. This will assign Ctrl+Alt+(Key) to run the Kill_Freelancer.bat
OK all open windows, saving any unsaved data.
To test this, just launch Disco and then hit the Ctrl+Alt+(Key) combo. Freelancer should close regardless of where you are in the game.