all you have to do is when you're finished, on the animations window, there should be something that says "repeat/animate" and a bar next to it. That bar should say "once" or "forever". IF you're animating, then that's how it should be.
IF you still don't understand, i'll bring up some pictures
i think u misunderstood my question, i mean how do u only loop a certain part of a animated gif not how long i want to loop it.. its kinda like i only want one part to only play once while the rest of the gif loops around