Thanks to BB for the pointers on Dolphin modes. I shall have a play with that.
I'm now in as a new user and it seems to work fine. I wasn't happy being in as root all the time and some things like browser clips didn't have audio. Anyway, I'm working well now and really won't be messing too much until after Xmas.
The only thing I shall try is make an up to date boot disc as backup. Also of course getting this new user set up fully.
Thanks, so much for all the help folks.