On Windows 7 computers with a limited amount of RAM (memory), diminished system resources can cause an overall system slowdown that can also affect Final Draft. The first thing to do is restart your computer and see if the problem persists.
If it does, right-click on your Taskbar (the menu bar typically at the bottom of the screen that has the Start button at one end) and click on Task Manager. You can also access the Task Manager by pressing Control + Alt + Delete on your keyboard and selecting it from the menu. Check to see if you have applications or processes running that may be draining system resources but may not be necessary at the moment. Exit these applications, stop these processes and restart your computer.
We have also had reports that setting the Desktop wallpaper to change frequently can drain resources. Go to Start > Control Panel > Appearance and Personalization > Change Desktop Background and increase the time between picture changes. Restart your computer and see if Final Draft (and possibly other programs) are more responsive.