In the Res-Q file selection screen, accessible by clicking the select files icon at the top of the main screen, add a filter to include "*.*" (without the quote marks), which means ALL files. To do this, simply type "*.*" in the "include files" box and click on the "add filter" button. You will now see "*.*" in the list of files to be included. Now, click the checkbox that says "modified files only" and Res-Q will sort through ALL files, picking out only those that have been modified. If you also check the box that says "reset archive bit", Res-Q will mark the modified files as having been successfully backed up. This way they won't be included again in the next backup, unless of course they are once again modified in the interim.