remote access

if i know the IP address of another computer is there a way i can remotly use it?
i have been bothered buy someone who feels it is ok to bother me but i dont want to go to the police and i dont have the money for a private investigator to catch this bad guy
if not what would i need?
i probably can get more information but i need to know what to look for.
im hoping to get on this guys computer and check him out but it would be nice to know this stuff so i dont give out this information to someone (or check if i already did)