Hmmm well, this is explained very well at the web page.
But here comes again.
I guess you have an x86 platform cause you also run m$.
Suppose you have one ide disk.
To install the bootselector:

fdisk -i -c /usr/mdec/mbr_bootsel wd0 
fdisk -B wd0

There you go.
Bye,

Mipam.