You said, "I'm trying to burn the HD images from the camcorder to a regular DVD on a burner that came with my 3-yr old Compaq desktop."
If you are copying the files from the camcorder to burn the DVD, then do that. There is no need for any video editor intervention. All you are doing is using the blank DVD as a place to hold data files. You don't need anything fancy. In theory, these AVCHD compressed MTS files on that formerly blank DVD can be played back using a BluRay player (including a PS3) connected to a HDTV. These data files can also be used to be imported to a computer based video editor capable of dealing with AVCHD compressed MTS files.
If you want that high definition video on the discs to be playable on a regular DVD, you need to know that regular DVD players cannot deal with high definition video. That video needs to be downsampled to a format regular DVD players can deal with - generally described as "VOB" format files.
The software that comes in the box with consumer camcorders is useless. Yes, I have heard of Pinnacle Studio, but it does not seem to be able to keep up with the likes of Sony Vegas or Adobe Premiere... admittedly, I only use Macintoshes (iMovie and FinalCut) for editing and rendering - my Windows/Vista machines are used only to ensure file compatibility.