I know nothing about Apple Mac's . The system is hanging periodically causing some annoyance to the user. Is there a monitoring tool I can use built in to the system? I'm not sure what OS is running but its 20mnths old if that helps. There is plenty disk space available and theres 256mb of RAM and it does not appear to be the problem. Possibly defraging the HD would make a difference but I dont know how to do this. Help.....