Some other operating systems (e.g. MS-DOS 6.0) appear to modify the MBR in their install procedures. It is therefore possible that LILO will stop to work after such an installation and Linux has to be booted from floppy disk. The original state can be restored by either re-running /sbin/lilo (if LILO is installed as the MBR) or by making LILO 's partition active (if it's installed on a primary partition).
It is generally a good idea to install LILO after the other operating systems have been installed. E.g. OS/2 is said to cause trouble when attempting to add it to an existing Linux system. (However, booting from floppy and running /sbin/lilo should get around most interferences.)
Typically, the new operating system then has to be added to LILO 's configuration (and /sbin/lilo has to be re-run) in order to boot it.
See also section 5.4 for a list of known problems with some other operating systems.