an ide drive (c), where windows seems to save the boot files, and
a scsi drive (four partitions e, f, g, h, where e and f are OS's; one for audio, one for other stuff)
i tested the stability and functionality of the os-manager. i installed 2 OS's on the partitions and started each one, then formatted one of them, started the remaining OS (worked), installed the OS again and started both (worked), then formatted the other OS and started the other one (worked, too). then i installed it again and started both OS's (guess.. it worked:-))
took me a whole day to try it out.
so if anyone is thinking about multiple OS's: go on
it's save