Six year-old Compaq Presario running W98SE. Came with McAfee, never updated as I jumped over to Grisoft years ago. I've just completed a Full System Restore. Have Grisoft AVG 7.0 and ZoneAlarm running. The old McAfee AV program was reloaded during SR. Question is should I try to uninstall it using Control Panel and/or CCleaner or just leave things alone and let it tell me at each boot that it's 68 months old without an update?

There is no reason to keep it, so uninstall it and use the HD space for something else.
Cheers,
John