The ubiquitous "Windows issues"

I'm having two issues, both minor, one kind of annoying, the other no big deal. (Windows XP Pro.) They are:

-My audio is not quite functioning properly. Driver is Realtek High Definition Audio (onboard sound, DFI Blood Iron P35 series board). When I play mp3s in iTunes, there's some static (for some reason this doesn't happen with Winamp). Using Ventrilo, voices will begin to stutter, then one sound will catch and stutter forever. No voices come through at this point. If I play a video with the Divx player, the sound has a high degree of static and is audible even with the volume bar at zero. These problems have existed for a couple of months (just discovered the Vent problem today, but I hadn't used it since the beginning of summer).

-Certain videos, when I navigate to the download folder they're in, will cause Windows Explorer to crash when played. Not really a hassle.

I'd like to at least get the audio problem figured out. But given that I've done the basics (reinstalled/updated drivers and programs, went so far as to pull the registry folder for the drivers), part of my concern is that these are symptoms of a deeper issue in the OS that I can't figure out, and that I may be looking at a full Windows reinstall. It's not a big deal to do it, but given that I always end up misplacing something on C, I'd like to avoid it if possible.

I don't think the audio problem is windows per say, maybe ITunes/driver conflicts with windows, winamp has no problem, so you know the music file is clean, Try downloading VLC ( http://www.videolan.org/vlc ) and play the movies and see if Windows Explorer crashes

try CCCleaner, and backup the registry before surgery, use EFRC( Eusing Free Registry Cleaner, it's free, after surgery)