Capture Fox is a nice little add-on that turns your Firefox browser into a one-click screen video recorder. The extension is available for Windows XP as well Vista.
Capture Fox can record all your activity inside a Firefox window or even the entire desktop screen and will save it as a video file. The program can also capture audio from your microphone.
Record Firefox Screen as a Video file
After installing Capture Fox, you’ll find a button in the Firefox status bar that serves both as the Start and Stop button. And while the recording session is on, you can check the duration of the screencast from the status bar itself.
While this is no replacement of Camtasia or other standalone screen recorders, it is still a good option for recording quick videos of your Firefox screen without firing an external program. Alternatively, you may use an online screen recorder.
Related: Screen Capture Web Page in Firefox