Welcome to the site.
I was a Windows Movie maker for a time
It was ok and did the job, but once you have the editing Bug. You need more Power to control things.
I moved up to Pinnacle Studio 9.0
Its ok for what i want it to do. It does do split screen but only after a hefty upgrade.
I have not used any other editing programs so cant coment on others.
Pinnacle has some stability issues, which can be a major pain soemthimes. But as a Next step from Movie Maker its a good bet.
Live from Norwich !
Sony PC1000E ( Stopped working after 13months)
Sony HDR-HC3 4Mega Pixels High Def Mini DV Broke
Canon HF 10 - Broke
Waiting for the Sony HDR-GW55VE
Avid Studio, + Pinnacle Studio14, Win7 64bit 12 GIG memory, Nvidia GTX590, twin 3D display, 2Terrabyte HD