MOUSE POINTER FREEZE

Hi Ya’ll!
freind’s PB2950 desktop,w P1@120mhz,24megsRAM,
2gigHD can’t use their mouse. Pointer appears
in center sceen at startup, but wont move. Can
navigate Win95 system some via KB. No other
Prob. apparent. Owner already tried new mouse.
PS/2 socket. Kids need comp working again for
their education. Advice would be appreciated.