Trados is known for not playing well with others, which is why installing Trados and Felix side by side isn’t strictly supported. But if you want to do it anyway, you can disable Felix when you want to use Trados, and then enable it again when you’re done. These two .bat files will do that.
(To download these from Firefox, you might need to right-click the link and choose “Save link as”)
If you installed Felix to a non-standard location, you’ll need to edit the paths in the files. Otherwise, simply double clicking on the appropriate file will enable and disable the Felix interface.
Note that Word, Excel, and PowerPoint should be closed before using the .bat files.