Originally Posted by archtoad6
Back up your menu.lst just in case . . .
I guess it can't hurt to back it up, but unless you do something really
strange the new install of Mepis will be in a different partition with its own /boot/grub subdirectory containing its own menu.lst file and the old /boot/grub/menu.lst will still be there untouched (but no longer used).
Once you have the new Mepis running, you can diff (kdiff3 is better and easier) the menu.lst in the previously used boot to the current one. If the installer failed to copy any important chunks from the old menu.lst, it is easy to copy them manually.