HDD dead?..Or am I just slow?

[Syribo]

I just can not figure out how to get my newest HDD to show up and work...

I posted a week or two ago, asking about external HDDs and ended up buying a third Segata Barracuda 7200.11 500GB drive, and the Antec MX1 for it..

Well, I hooked everything up, the MX1 light is on showing that it is indeed working.. I connected the eSATA wire from the drive to the eSATA port coming from my motherboard, on the back of the computer...

...But... I forget how I am supposed to format, partition or whatever.. The new drive is not showing up when the system POSTs and then when I put in my Vista DVD and I get to the screen where it shows the partitions.. The new drive is not there either.

This is what happened when I first built this computer and it turned out one of my Seagate drives was dead... Am I doing something wrong?? I am drawing a complete mind blank on how I am supposed to get this thing working... I REALLY hope it's not DOA.. That would make it 2 out of 3 Seagate drives that were DOA for me :( Please help? Thanks :)

[nitrobass24]

make sure the eSATA port is enabled in the BIOS

[Syribo]

I didn't see anything saying to enable eSATA, just SATA.

So I tried taking the drive out of the enclosure and set it up in my system and set it up using a SATA wire instead. It showed up right away when my system POSTed.. So then I went into the Vista setup thing to format the drive and create the partition.

While the setup was loading, I got a BSOD. Restarted, got back into the Setup menu and formatted the drive. Then I restarted and now I just keep getting a:
BOOTMGR is missing
Press ctrl + alt + del

So... Then I went into Windows Repair, through the Setup DVD, and it repaired, supposdely.. Retsarted and I'm still getting the BOOTMGR error. I took the new drive out, restarted and still getting the same message.. or a BSOD.

Now I'm stuck here... I can't even get Vista to start up... I really hope I don't have to format.. I'll be really unhappy... Anyone know WTF is going on???