Support page for your system, M7480 System.
In my experience...stuttering results where the hard drive needs to be defragged and/or the CPU is being overtaxed and the system has onboard sound.
Last time I experienced such (quite a few years ago), installing a PCI sound card took care of it for me.
In your case...I suggest uninstalling the current audio drivers...and then reinstalling them.
I would also run chkdsk and then run defrag after that.
To run chkdsk /r: Start/Run...type chkdsk /r (exactly as shown) and hit Enter. Type Y in response to new screen and hit Enter. Reboot the system...the command will run before booting into XP.
To run defrag: Start/Run...type cmd and hit Enter. On new screen, type defrag C: (exactly as shown) and hit Enter.