Hi Jack, thanks for your reply. No errors, just no updates. Silent Night checks the system and lists what's there and what should be if there's an update but the installer just spins endlessly. The same thing happens in software update. It's not a problem as much as not being up to date.
Thanks HWTech, I'll try safe booting and see if I can get it to update. Since my post, I've also been to mr Macintosh dot com as referenced by the electric light company. I've downloaded new installassistant.pkgs but they don't change anything either.
As this is an older Mac, I'd like any security, etc updates apple puts out.