problem in probe my harddisks drive

[erik freaks]

helo...
please help me I got problem when I install freeBSD 6.2, when I try to make
partition I got message:"Disk no found!...",
but when I install freebsd 4.7 everything fine...,please help me.
my PC spesification:
1.Motherboard:Asus p4p8x
2.proc: intel P4 2.0GHz
3.VGA card:nvidia
4.Harddisk : Samsung 160Gb
...
can you help me plaese, how to probe ny hardwaremanually in freebsd 6.2.
help me...