My laptop is set up to dual boot Windows 10 and SL7. I had
backed up all my Linux files and made a Windows 7 style
backup of the Windows partition. Then I accidentally exited
Windows by 'restart' rather than 'shut down'. The result is I
cannot reboot the Linux. I get my usual grub menu but trying
to start Linux from it gets (after a couple of warnings which are the
same I had before):
Welcome to emergency mode!.....
and trying either of the suggested 'systemctl reboot' or
'systemctl default' leads to a message
Error getting authority: Error initialising authority: Could not connect: No such file or directory (g-io-error quark,1)

I can boot from a Live USB and mount the linux partitions. I am pretty
confident therefore that no data has been lost from them.

Is there a way to recover short of wiping the disk and reinstalling
from the beginning?

Malcolm MacCallum