Question : Problem: troubleshooting High CPU performance spikes

What troubleshooting suggestions do you have for a machine that is spiking at 100% processor usage when this user is working in a propietary application used for scheduling music at our radio station. The machine is running Win XP w/SP2

Answer : Problem: troubleshooting High CPU performance spikes

See if Process Explorer or What's Running will do it for you. Both show what is using what, and how much of it.
I kind of like Process Explorer a little better, myself.

Process Explorer  
http://www.sysinternals.com/ntw2k/freeware/procexp.shtml

What's Running
http://www.whatsrunning.net/whatsrunning/main.aspx