[boot loader] default=c:\nbsd0.bb [operating systems] c:\nbsd0.bb="NetBSD (harddisk 0)" c:\nbsd1.bb="NetBSD (harddisk 1)" c:\nbsd2.bb="NetBSD (harddisk 2)"The bootblocks are created with "dd if=/dev/rsd0a of=nbsdX.bb count=1 size=512". Please note that if you don't have NetBSD on your first disk, you'll have to recompile the bootblock and install it, before you can do that command (with differenc /dev-file, of course. (For the recompiling you need some minor tweaking in /usr/src/sys/arch/i386/boot, but I can't remember what).
WARRANTY: No warranty. The above worked for me, I can't guarantee if it will help you. If you have updates I can merge them in, but be aware that I can't help you much beyond that, as I'm not a PC or Windows guru!