ok i put my 2nd hard drive in and when i turn it on it just loads the bios screen and windows doesnt load but when i go into the bios i reconizes the hard drive and its size blah blah. But when i take it out it load perfectly.
Yeah, if you jumper settings are incorrect the comp won't know which HD to boot up from.
P.S. Make sure that the Master dirve (1st HD) is connected at the end connection plug on the data cable and that the slave drive (2nd HD) is connected to the middle connector.
... just goto BIOS and change the primary boot drive 