Hi, I am busy trying to build a screensaver where a camera follows a path at a very slow speed.Along the plane, spaced out evenly are all my pictures on Planes.My trouble is that the camera doesn’t want to reach the end of the plane.It gets so far and then just resets to the begining. Anyone know what’s wrong.And the other thing is, how do I convert the final.blend file to a .scr file. thanks all 
first, are you making an animation to render or for the game engine?
[well, this only matters to a screen saver]
well anway you probably don’t have the start/end frame nubers set up correctly, either in your ipo actuator [if for the game engine] or in the render buttons [if to be rendered as an anim]
there was a patch submitted for 2.36 which will allow a standalone runtime to be renamed to a .scr and work as intended as a screen saver. The blurb of the patch says you can right-click .scr files and choose install to make them show up in the screen saver list. I haven’t played with this feature, and am not sure if it has been committed [if it hasn’t it probably will be]
I do not know how you would play an animation [avi or somesuch] as a screen saver, but it is possible.
You may have so set your End frame count higher. Look in the Anim Panel in the RenderButtons Window.
Just save your blender animation to an avi-file and play it with a screensaver that can play avi-movies
Here’s a link to one (but there are many more): http://www.freewareweb.com/cgi-bin/deskdb.cgi?ID=331