Can’t run commands from WinNT 4.0 Client

I’ve recently been asked to “fix” a local network as a favor and encountered a problem I haven’t seen before; it’s a Windows NT 4.0 network, TCP/IP, SP6a, everything seems right except 3 of the 6 NT 4.0 Clients can’t run PING, NET USE, TRACERT, etc., it returns the error: “The name specified is not recognized as an internal or external command, operable program or batch file.”

Any help out there?