PC wont boot with added HDD

Try moving your boot drive to SATA1, new hard drive to SATA2 and the optical drive to SATA3.

i tried your suggestion with no luck,

right after i tried that i unplugged the new hard drives SATA cable expecting it to boot, but it did the same thing again.. until i unplugged its power cable as well then i could boot into windows

any ideas?

What motherboard are you using???

motherboard is- abit ip35 pro XE

Also-
550W corsair power supply
core 2 quad @ 2.4 ghz (Q6600 i think)
4gb Gskill
Saphire radeon 3870 HD gpu
320 GB sata hdd
120 GB (old style) hdd

i would like to add that the ip35 pro motherboard has a digital display on the the actual motherboard that gives 2 digit numbers indicating the status of the computer (error codes or everything is fine codes)
When the bootup freezes at the blank screen the display reads the same code as it would if everything was running properly

Right now all I can suggest you test is as follows....

1 Return your DVD and orig HDD to their org ports... DVD/sata1, HDD/sata4 as you originally stated.

2 Try booting with your new drive attached to all the other available ports, one at a time.

3 Try booting with only your DVD and the NEW HDD attached. Even try loading an OS on it to verify it works.

I find it odd that one of your tests prevented the computer from booting UNTIL you unplugged the power cord to the new drive as well. That really shouldn't keep the computer from booting unless there is a problem with the power cable or the drive. You would think the drive is OK since the BIOS detected it properly, BUT that isn't always the case.

I checked the MB manual concerning the SATA ports and didn't notice anything that jumps out at me.

Even if my suggestions don't help you out, PLEASE post back if you finally get the problem sorted.

will do, thanks for the suggestions