Strip Windows to make Stablized Recording

I record HDTV from my Cable Box to my Computer. I estimate about 30% of the initial recording contains a “glitch” that makes recording to dvd impossible. Often the original first recording is viewable but cannot be re-encoded to compressed format. To trouble shoot this I have noticed better results if I close/kill all processes except those required for the stream capture itself. EG–turn off IE, close explorer.exe, try to shut down the anti-virus but it won’t close. The error rates like bad synch on re-encoding has almost dissappeared but still remains. I turned off “task.mgr” process and found my system recorded but there was no sound so now I record with task.mgr going from 0 to 6 mb for no apparent reason–but maybe doing something to activate/keep active the sound capture?

Anyway==I have a second computer running Win XP that I would like to strip the OS for doing nothing more than recording the .ts stream from the cable box and then access the computer over my home lan to move the recorded file to my main computer for editing and burning.

Any advice on how heavy to go in and delete programs? My fantasy would be that on turning the computer on, the only program that could run would be the capture program, but I assume that is unrealistic. Thanks