The only times it goes this way is for avi,mpg,mp3 etc(movies)..Sometimes, one click on the file, and usage goes up to 100% and my system "hangs" for 5-10 minutes with almost no hard drive activity until it finally free's up. This "hang" problem happens frequently and randomly. I checked the processes and when my system "hangs" I notice "explorer.exe" says 99 CPU usage. And it seems like everything in the list has more MEM usage as well .. : ) enjoy

replace the memory, and dump the sp1. its a pain in the wazoo

You may want to check and see if you have all the codecs for your system. Sp1 really Kjan has more or less all the critical updates that microsoft has found (meaning patches that prevent users from gaining access to your system)Here is all the information link http://support.microsoft.com/default.aspx?scid=/support/ServicePacks/Windows/XP/SP1FixList.asp Not sure of the progam that you use. But i have seen a increase in cpu usage on programs like divx viewed using the divx player. Microsoft player with the divx codec seems to be much more stable with less cpu overhead.