If you are on Windows 2000 and LimeWire is eating up your CPU , there is a easy fix :

Open taskcontrol or taskmanagment ,
Go to the "proceses" tab ,
Find javaw.exe , right-click on it ,
Then change it priority to "low"

When I did this , my CPU load went from 100% to 60~70% .
And Windows was happy again !

In theory this works with every program you have running , some crash tho ...