.. the problem listed brings-up an old conundrum; using Divx for editing.
In short, no; there is nothing else out there that is as simple as Movie Maker which
will keep the file sections in sections & produce small video files.
ABC Edit 123, AiST & MGI used to offer such and DDclip used to be extremely useful however,
with the introduction of Windows XP .. most of those softwares no longer work after being
loaded onto the hard drive. Virtual Dub used to be able to load .asf files until MicroSoft said, "NO!"
Unless you want to retro-back one of your other older computers to use Windows 98SE or ME,
using those programs listed will not function properly with XP or newer. -- sorry. ... however,
should you care to switch-over to a Linux-type system, there are many NLE Editers which still
work along the lines in which you are looking for.