You may not need to fix it. Here is what it is (from M$):
"Still Image Monitor (Stimon.exe) is a program that is installed by Windows Millennium Edition (Me) and Windows 98 when a Universal Serial Bus (USB) scanning device is successfully enumerated. It is configured to start automatically at start(size 5833 bytes, updated 10/22/2000 4:06:00 AM GMT)"
If you do not have such a device in your system, then all you have to do is go into System Configuration Utility, Start Up tab, and uncheck STIMON so it doesn't load on start.