error messages/freeze-up

this morning i noticed my screen saver had frozen;there was a message ms/underwater screen saver has caused error.this is the first time i had this happen since i bought the pc 2yrs ago. i use hp/pav 6736/win-me.using norton sys/works with firewall&auto-protect disabled. we use our system for e-mail & info gathering from net.we don’t use o/s for filing info. i tried to use my hp software sys-restore and recieved msg. unable to restore;;must repair errors;go to control panel; select sys.properties tab;;;that’s where i stopped .i could’nt find system property tab in the control panel. thanks jerry