I'm Having Alittle Trouble

I Got The AVS Editer 4, The Features Is Great And Everything But, It's Just When I Try To Publish A Video It Take Like 2GB Of Memory, I Have No-Idea What The Hell I'm Doing Wrong,All I'm Asking Is If You Know Anything That I'm Doing Wrong Please Tell Me,How Do I Make The Video Take 81MB Of Less Like The Windows Movie Maker Does When I Publish Videos,I Want To Stop Using The Windows Movie Maker,I'm Not Saying Its Bad Its Just That If I'm Paying Monthy For This AVS Software,I Need Some Help On How To Use It,Cause Youtube Won't Upload A Video File That Is 2GB(Gigabytes)...Please Help Me Or I'll Be Paying Money For Something I DOn't Know How To Use.