I have installed XP SP3 on my SATA HDD-320 Seagate Baracuda- and have downloaded a lot of stuff- movies- games etc. . all was fine
and i was able to use all the functions properly. then i thought of updating the system online from Microsoft updates
now the HDD is not getting recognised- XP is not booting - SATA HDD is not recognised even in the bios.
i have 2 SATA HDDs, 80 GB and 320 GB wanted to use both together but am in trouble now. as primary and secondary slave dont work. am presently booting frmo 80 GB SATA but th3 320 is not recognised in system nor in bios
my Motherboard- Intel Pentium 845GNTL- supports 4 SATA connections
-1 GB RAM DIMM2- 512 2 peices
i am giving all info which may be essential for diagnosing- hope it helps.
looking forward to reply soon.

what system bios(brand) is your computer using?

- my system bios is intel-( i hope i am right on that) where can i check it ???
in case i am wrong.
i have all the drivers updated

Is there user manual for your motherboard,cause the technical data are into it.

Did you update the SATA driver from windows update? Sometimes these drivers are bad. In Devcie manager you'll see an option to "Roll back" the driver, which may help.
System restore may help.
Is this a RAID setup?
Is the SATA controller enabled in the BIOS?

\There's no "slave" designation with SATA.

download this safe program ,run it and on the motherboard tab it will show you bios /name ,version and date .

thanks for that help.
And my drivers are all updated from windows update.
Mainboard Vendor Intel Corporation
Mainboard Model D945GNT
BIOS Vendor Intel Corp.
BIOS Version NT94510J.86A.3996.2006.0908.1329
BIOS Date 09/08/2006

thanks for that help.
And my drivers are all updated from windows update.

that good ,but my choice and the choice of many is not windows updates for drivers ,best to get them from the manufactures website

pranavv, the biggest issue is that your hard drive is not getting recognized in BIOS. You should try changing the data cable and the power cable and also try different SATA ports until it is recognized. When it is recognized, you can easily select it as boot device from BIOS. The bottom line is that it should be recognized in BIOS otherwise it's a hardware failure.