ok i c. this has happened to me too. if you use windows movie maker then i can tell u how to. so if u do, u need to make the video how evr u want it to b. then wen ur done, publish it to your computer. then some page will say to either make it the best quality, or to shrink the size. it shuld b the second option. the second option has a box with a number in it. raise the number all the way. usually it would be around 50 MB. but the cool thing is, is that it still has good quality.
if u need anymore help just PM me.
Quincy Cintron