With video recording or any other activity--I can record while web surfing or opening folders but "some" programs still require all computer resources to initially open leaving a 1/4 second glitch in whatever I'm recording. I just schedule what I'm going to do so that I won't open programs==I make sure they are all open and running before the recording starts. I'm sure the same will apply to encoding.
Take a rewriteable disk and just max out everything you might do like play a game while downloading some other stuff==then check your disk for errors. I assume you will get a few.==so be judicious. ((Use a short 10 minute file to test this all out))
Also==I now you can setup task manager in Win2000/xp so that resource hogs won't take over the computer when starting but I don't know how effective those are.
I run AMD so I don't know but I "should have" built a hyperthreaded rig to help avoid this problem==although it is manageable but I would like to see how hyperthreading handles this since that is its forte.
And of course, adding the maximum ram might solve the problem if any of your glitches are caused by inadequate ram.
Finally (!!)==right after I built my machine after waiting 12 months for a price gap to open, I noticed the same performance was on sale for about $300 total==so build a cheap 478 based machine and use it just for encoding if you can spare the change.///bobbo.