Perhaps after install you have two active partitions or have not it at all. You must reboot with windows boot floopy and then use fdisk set one active partition (I recommend unix partition). Reboot and at the boot prompt enter:

Boot:
:dos

or you can boot other system using the bootos command:

Boot:
: bootos dos_16

or
: bootos dos_32

If you have trouble with this write your install procedure more detailed

Best regards