Not detcting sata drive...

[Caesar]

My computers not detecting my new seagate 160 gb SATA drive .I get a booting disk not detected message when its connected.I dont want to make SATA the boot disk and want to boot from my older drive.The guy from whom i bought who is also helping me install says the only way to solve this would be to reinstall my windows XP and use SATA as the booting disk.I prefer to not reinstall windows so is there any other way??
My OS:Windows XP
Mobo:Asus A8n-SLI SE

EDIT:From what the guy helping me install this said,i think the SATA drive is appearing in bios.

Thanks.

[shantanu]

change the boot configuration in BIOS.. set the first boot device to older drive !! thats all you got to do.. and also check for the SMPS(maybe two drives are consuming more power)..

how much watt your SMPS is ... and also tell your system specs... and which version of windows XP r u using... (means if SP1 or SP2 is not installed then SATA wont get detected in windows too)