svchost.exe problem?

A few weeks ago, I began to get an error message while working in Win2K saying “svchost.exe has generated errors and will be closed by Windows. You will need to restart the program.” I do not have WinGate installed, nor Aventail software installed. Nor do I use dial-up connections (DSL high-speed internet connection). Recently, my CPU usage climbs to %100, even when running Outlook and my web browser; consequently, my computer runs very slow, and sometimes freezes up requiring me to Ctrl.+Alt.+Del. Sometimes I even have to perform a hard shut down of the computer because I cannot even get into Task Manager. One friend suggested my “svchost.exe” is missing? He said I may have to perform a reinstall of Win2K. Any suggestions?