High CPU Usage when Converting and Burning

Okay i got a new computer. Its specs are AMD athlon 64 X2 dual core processor 4400+, 2 gig of ram and a standard edition NVIDIA Geforce graphics card 6150. My problem is this. When i first got the computer i could use convertxtodvd winavi cucusoft avi to dvd converter or any one for that matter. Never had a problem would convert and burn fine at like 30% Cpu usage. Now a couple months later it runs at 100% cpu usage and will shut down after 5 minutes. Doesn't matter what program i used. Trust me I've tried em all and it does the same thing so I'm guessing its not the software its the hardware.Any ideas?