CPU Speed for DVD-R

[cactus]

I know this one should be easy, but I have a 450mhz computer (I know I need a new one), but the guy at the computer store said that a DVD Burner would work fine since we had the minimum speed. The way its been working is that I can only burn smaller games about 2.5 gig or less before the whole system freezes. Any idea what minimum speed I should really use? I'm using Recordnow Max and looked at Burn-Proof in the index, but I can trigger it when I'm setting up the burn. The help doesn't help too much.