Small Business Server 2000, SP4, running veritas backup exec, McAfee EPO. Clients utilising ISA server for internet access. Following a reboot the server works fine, however, through the day the server loses certain functionality,examples are, internet access icons show no activity despite being connected and active (never seems to disconnect), if you right click on them to disconnect it will not disconnect. Right click within event viewer does not display the properties window as expected, however, when the event viewer is closed a message appears requesting all property windows are closed before closing the event viewer. Also backups are failing to read media. Within active directory, if you right click for properties when logged in as administrator it says you do not have permission to view this item. All these functionalities return if the server is rebooted.
We have used various tools looking for adware/spyware etc and the server is virus free according to McAfee.
any suggestions on where to try next would be greatly appreciated.