What dimensions to use and how to convert this to 4 : 3

[perfection]

I have several mpeg clips which i had captured at 480 x 576 for later SVCD recording. Now i have changed my mind and would like to insert them as they are into my powerpoint presentations - the problem is ppt will play them at their native dimension 480 x 576 which looks like a vertical standing rectangle. I's preefer to show this as is the more common horizontal rectangle... - what dimensions (nearest) should i change to and what freeware tool is recommended for this.

BTW how does one get windows media player to display video in 4 : 3 aspect

[guns1inger]

You can't get WMP to play 4:3 correctly - it sees avi as 1:1 pixel aspact ratio except in a very few circumstances (DV, DVD playback). In short, it is a poor player. Of course, in the case of power point (another poor application, IMO), you are limited in how you display video.

Try resizing to 480 x 480 and see how it looks.