I just remembered trying to dual-boot Linux and W95 (and maybe ME at
some point) and having to either do Linux second, or save/restore the
MBR, 'cuz Windows overwrote LILO (which AFAIK is in the MBR not the
partition portion).


*Vanguard* wrote:
It can be confusing which boot[strap] program is being talked about.
There are 2 of these: the MBR bootstrap program (in sector 0 of the
disk), and the partition boot program (in the first sector of the
partition).

There's the "hardware" bootstrap program in the first 460 bytes of
sector 0 of the first physically scanned hard disk that the BIOS will
load into memory and start its execution. This is the loader program in
the MBR (Master Boot Record) used by the BIOS to "bootstrap" the system.
Its job (for the standard bootstrap program) is to read the partition
table to see which partition is marked as active and where that
partition starts, then load the OS boot program in the first sector of
that partition.

There's the "OS" boot program in the first sector of the partition in
which the OS resides. This is the one that actually starts loading the
operating system. If you install multiple operating systems in parallel
within the same partition, each will write its loader program into the
"boot sector" of THAT partition. They do not (or should not) write into
the 460-byte bootstrap area of the MBR (unless the bootstrap program is
missing). To keep the various DOS/Windows products from stepping on
each other's loader program in the partition's boot sector, I install
them into separate partitions. The MBR restore was an optional step
that I could have and should have avoided.