Set the menu choice for next reboot without access to conf file?

[David Mathog]

We have some systems which are remotely administered and dual boot linux
and Windows.  Under linux there is access to the grub config file, but
under Windows there is not.  The default grub menu option boots Windows. 

On linux

  grub-set-default 1

will tell grub to use the 2nd menu option (and so boot linux instead of
Windows)) only for the next boot, so long as the grub config file is
appropriately configured with "default saved".

If this command were applied from Windows would "grub-set-default"
require access to the grub config file, or does grub-set-default just
store an integer somewhere in the MBR, or elsewhere in the first disk track?

Thanks, 

David Mathog
address@hidden
Manager, Sequence Analysis Facility, Biology Division, Caltech