Copying LInux MBR to boot from WIndows BootLoader

To save the current Linux MBR type
dd if=/dev/hdaX of=/bootsect.lnx bs=512 count=1

where hdaX is the device in which you installed the MBR and /bootsect.lnx is the file in which you whant to dump it.

Then, to use it from Windows Boot Manager, edit c:\boot.ini adding
c:\bootsect.lnx="Linux"