Other possibilities are that you've turned on some program option, or run some part of a program, without realising it. The MS "FindFast" thingy will start scanning your hard disk if it thinks you're not doing anything. Anti-virus might start doing an automatic scan. "Scheduled tasks" (see Control Panel) might be running something. Things like that.

When you go to Task Manager, which of the tasks are using that 46%?

Also, have you checked the contents of the Start menu "Startup" folder? On Win98 you can use "msconfig" to see what else is being run, but I don't know what you do for this on WinXP.

Graham.