new SATA drive recognised in BIOS not by win 7

Hello -
I have two drives on an old computer.  I've just removed a SATA drive with MOLEX connector (power) , and replaced it with a new seagate drive , using a MOLEX to SATA adaptor.

OS (win 7) and programmes are on a (rather full) Maxtor 80 gb scsi hard drive.
docs were on the second drive, now replaced but inaccessible (for formatting etc)

The drive is new and will need to be formatted.

Now the new drive is recognised in the BIOS / Setup screen, but windows does not show it in the My Computer screen.

Phoenix bios read thus:

IDE channel  0 master  =  [none]
IDE channel 0 slave    =  [Maxtor 65Y080L0]
IDE channel 1 Master  =  [Artec WRR-52X]
IDE channel 1 slave   =  [none]
SATA channel 0 Master  =  [Seagate ST31000340NS]
SATA chananel 1 master  =  [HL-DT-DVDRAM, GH24]
sata CHANNEL 2 MASTER  =  [BONE]
sata CHANNEL 3 MASTYER   =#  [NONE]

aUTODERTECTION ON SEAGATE DRIVE SHOWS IT UPO AS
CAPACITY 1000 bg

CYLINDER    65535
HEAD   16
PRECOMP    0
LANDING ZONE   65534
SECTOR    255

So I need to get windows to recognise it.

ON a further note -
the intention here is to pass the PC on to my son who intends to reformat or remove the maxtor and run linux.  May this have any bearing on my next move?
Either way, I'd really like to know why it doesn't show up in my computer since it's recognised by the BIOS.

Kind regards,

Alex