WIN98 DUN SECURITY LEAK

HAVING A PROBLEM WITH MY DUN CONNECTION ON MY WIN98SE IN WHICH IT IS BEING USED BY SOMEONE TO FOLLOW MY EVERY MOVEMENT! IT IS CONNECTED OUT TO THE FILESHARING PORTS 137,138,139 AND REFUSES TO FUNCTION THE WAY IT WAS INTENDED!
ALSO MY ISP IS REFUSING TO ALLOW MY BROWSER TO MAKE CONNECTIONS UNLESS THE FIREWALL IS SET TO ALLOW INCOMING CONNECTIONS THAT I OBVIOUSLY DONT WANT!!
MY BROWSER USED TO WORK FFIINNEE THAT WAY!!

ANYONE HAVE ANY EXPERTISE ON THIS ISSUE?

THANKS