Medal Of Honor plays too slowly online after about 16=5 minutes

[Tunnel Rat]

I was playing MOH online for over a year when I had to reinstall win2000 OS. After my reinstall of MOH/AA/Spearhead, it plays OK for the first 15 minutes or so, then my processor maxes out to 100%. I amn running low graphics settings, have plenty of RAM open, including virtual RAM, and I have the same video card and video RAM, which was more than adequate before.

I have road runner cable and usually have the lowest PING in any map.
256MB RAM, 1.0 GHZ Athlon Processor.

Any ideas?

Thanks!