I changed my os from 2000pro to XP because my 600mhz Epia mb would not shut down correctly under 2000.
After getting everything going I started Frodo and it ran super slow and choppy, my CPU was average was 70-80% and jumped up to 100% for long periods of time when I changed songs and this was with Frodo in mini mode. I tried WMP10 without Frodo and had the same problem.
Since there is no uninstall for WMP I used restore to go back before I installed WMP10. This brought back WMP9 and fixed the problem. Now my CPU is about 12% and my boot time had dropped by 15 seconds.
I hope this helps.