Specs:
Windows XP, latest updates
1.7 ghz Pentium 4
1 gig ram
DirectX 9.0c
NVIDIA GeForce FX 5200 with 256 meg RAM
OpenGL 2.1

The story:
Okay, I had an older system laying around that I figured I would try turning into a mini-media system to connect to our TV. I put together a lot of older parts, got it into working order, etc. and hooked it up and voila'...slower, but usable system that displayed to the TV.

It could run some things decently. I put in iTunes, it played video okay. Not great, but okay. Played Hulu and since we have a 1Mb download rate, the minimum for their site, there were some choppy moments when watching their shows, but I found that (sadly) changing resolution to 800x600 seemed to help with the issue when running full screen.

I downloaded the application called Boxee and installed it. It wouldn't run; apparently the video card in the system supported OpenGL 1.2, and needed at least 1.4. I bought a cheap card, the 5200, with four times the memory in it and support for OpenGL 2.1.

Installed, everything seemed fine. iTunes seemed to run fine, the video driver (PNY video card) came with OpenGL 2.1, and Boxee finally ran.

I then upgraded to the latest drivers for the video card and ran the DirectX updater from MS.

After that, the OpenGL Extension Viewer wouldn't run. It just stayed as an icon in the task bar. Also, any and all videos in iTunes stuttered and went out of sync horribly. Unwatchable. I tried watching Hulu video in Boxee, and it displayed video like it was a series of stills in a very bad powerpoint.

Playing straightforward audio-only came through fine, no stutters no hiccups.

I tried system restore to roll back updates to pre-directX updates (I thought that seemed to be the time that triggered the weird behavior), no joy. I tried uninstalling and reinstalling the video drivers. I installed updated audio drivers (ensoniq audiopci), nothing helped.

I finally wiped the drive last night and tried reinstalling everything and restoring my iTunes content via an import from a backup. Fresh install, no updater on the video card or directx.

the problem was still there although I haven't tested Hulu, the iTunes player is still stuttering like crazy if I play video, fine if I play audio.

I know the processor isn't high in heft, but with one gig of RAM and the fact that it seemed to do okay before I thought that the problem must be software related. Has anyone else run into this sort of issue and have a solution other than "buy a new computer"? What specs seem to work with video at the low end for you? Right now the system is of little use other than keeping my music library and iTunes apps synced with my iPod.