Hi,
I'm building up a system and I'm having some troubles with HDD. When I plug it into the IDE 1, Bios says that there is no HDD in the system and tells me to check the power. When I plug the hard drive into the IDE3, which is Raid, the Bios identifies the hard drive, but Windows XP disc says that there is no HDD in the system. I have only 1 HDD so i cannot go with Raid. So what do I do to make the Bios see the HDD when it's on IDE 1?

make sure the selector pins is set correctly. The pin is located at the back end of your hard drive probably next to the ide cord.

Make sure it's set to "master"

Look on the hard drive and it should show a picture to where to place the pin to establish a master position.