MPEG2 codec question -- how to install?

Archived from groups: microsoft.public.windowsxp.video (More info?)

This is probably a pretty basic question, but I've managed to confuse myself.
The MPEG2 codec that came with Roxio VideoWave7 is crashing Windows
Explorer, Roxio, etc when I browse to a folder containing MPEG2 files. If I
disable that codec, the system doesn't crash, but Roxio can't see or open the
files anymore.

I tested by opening the MPEG2's in WMP10; it gives me the error message that
a required codec is not installed, but then the files open anyway and play in
WMP10. (?)

I found a couple of MPEG2 codecs online. I've installed them, I think. But
I'm fairly new to codecs, and don't know if other programs will automatically
use the codecs and be able to work with MPEG2 files? Or does every software
program use only its own codecs?

I found a utility to view/install/uninstall codecs. It shows my MPEG2
codecs as installed, but lists them under "Directshow Filters" instead of
"Video Compressors" in its categories? Is this correct?

Apologies if I didn't ask this quite right. Thanks in advance for any
insight.