WIN/2000-PRO. VIRTUAL MEM PROBLEM

HI THERE!
I AM NOT ABLE TO LOG INTO WIN-2000-PRO WS,
DUE TO VIRTUAL MEMORY PROBLEMS.
I DON’T LIKE TO RE-FORMAT AND RE-INSTALL WIN-2000.
MEMORY, AND HDD FREE SPACE IS OK.
Q: IS IT POSSIBLE TO FIX WITHOUT RE-INSTALLING EVERYTHIN?
Q: HOW?

EPHRAIM FRIEDMAN