Windows Movie Maker is a Pain

I have rediscovered that my Sony camcorder will not work with Windows Movie Maker.  For the last year, my Sony HDD worked perfectly with WMM; however, as you know, my PC hard drive broke, so I needed a new one and consequently needed to reinstall Windows.  I can't for the life of me remember how I got WMM to edit my Sony videos when I got this camera last year, and I've been looking for three days now.  Last year, somebody online gave me a lead/link to something that made WMM work great with my camcorder's videos.  Of course, I didn't write it down. This year, all I can get on the Net is that I need 'another program' in order to convert files to make WMM work.  I don't.  I know that.  I used WMM for a year without any additional program to convert files.  As you can imagine, it's frustrating.  I'm using the iSight on the Mac to make videos at my desk, so don't expect any videos "from the field" until I figure this out.