So let me get this str8. You have windows and mdk on ur pc. are u still able to load mandrake. if not, re-install and make sure u select lilo as the bootloader. if you can access mdk, open control center (not mandrake control center) -> click 'system' --> and click 'boot manager' -> then click whatever tab you want to use to edit the bootloader file. as long as you know where mdk and windows installed it should work fine. this is what i have, if it helps:
append="devfs=mount hdd=ide-scsi acpi=off quiet"