How do I set my default QT settings to "loop"?

I mean how do I make it my default? My work involves opening hundreds of QT files but I need them to loop and I'm tired of hitting ctrl L.

If the Windows version of the QT player works the same as the Mac QT7 player, then there is no "Preference" to do this. I.e., the player's "Loop" playback setting is automatically reset to "False" each time the app or a new player window is opened. The only way to automatically open a file with the "Loop" option set to "True" is to store this preference in the file itself, in a "reference" file pointing to the original file, or QTLink file pointing to the URL of the file stored online. Since these options entail more work than simply pressing the keyboard shortcut—I assume you would not be interested in using them. This leaves the option of using an alternate player like VLC. E.g., the Mac version of the VLC player remembers the active "Repeat All" ("Loop") setting in effect when the app was last closed and, therefore, will automatically play and loop each new file opened in the app. If the Windows version works the same, this may provide the workflow you want.

Open an audio or video file and click the control and l (el) key.