Not found msconfig in Win2000

Trying to remotely support (phone) office PC (1GHz Duron, 256MbSDRAM) under Windows 2000 Pro (stand-alone). Initial problem with modem/internet connection, results led me to believe some other app was interfering with aol - tried to Run msconfig to selective startup, but 'file not found, path invalid' resulted from Run command, and nothing found under Search. Sure it ought to be in C:\WINNT\System32, but sister assures me it's not there. Had trouble locating it from my own machine, Run didn't find it, but Search did. My version also specifies it as an SP4 build - surely it's present in 2000 before SP4? Would find it a lot easier to troubleshoot if I could disable Startup group. Any tips for locating msconfig, or accounting for where it might have moved to, or how to do similar without it, much appreciated. My sister's tearing her hair out.