Sorry - should have looked up single user mode for myself. Haver now done so, implemented your suggestion (although I needed to modify line 1 to "/sibn/mount -uw /" as described by the terminal display). All is now well - many thanks for your sapient advice.
How does one get into single-user mode? My laptop hangs on start-up, and I get the message "The underlying task reported failure on exit" (I did the same as Cantabiles) when I run the Disk Utiliyu from the OSX start-up disk
Thanks
