I'm locked out of machine as will not accept password as I shut down while using French keyboard
Or you could change the password to something "keyboard language neutral" via single-user mode. Quoting from Mac OS X Hints


  
  Boot into single user mode (press Command-S at power on)
  Type fsck -fy
  Type mount -uw /
  Type launchctl load /System/Library/LaunchDaemons/com.apple.DirectoryServices.plist
  Type dscl . -passwd /Users/username password, replacing username with the targeted user and password with the desired password.
  Reboot