Upgraded my HDD, but the new drive isn't being recognized.

[randomlysid]

I have a 2007 MacBook Pro (non-unibody) that recently started freezing / lagging. Further investigation revealed 300+ errors on the hard disk so I decided to swap it out.
I bought a Hitachi 500GB 7200RPM drive and did the upgrade my self. Now, this is my first time doing a hard disk upgrade, so I was exceptionally careful and I'm pretty sure that I got all the connections secure, no loose contacts etc.
However, when I tried to use the install disk image on my external HDD to format + install the new disk, it does not turn up in the left hand side column where it should.
Am I doing something wrong?

- Thanks, I'd really appreciate your help.

 

[stridemat]

It needs to be correctly formatted as Mac OS Extended Journaled. Boot up your Mac with the OS disks in and select Utilities > Disk Utility from the menus at the top.

 

[randomlysid]

My optical drive is dead; I'm trying to format it using an external hdd with a bootable image of the install disk.
When I turn on the computer, hold Option and select "Mac OS 10.4 install disk on Drive 'boot' " It takes me to the OS installer. I quit the installer and select 'disk utility' from the utilities menu. Here's the problem, it should show the new hard disk so I can format + partition it. However, only the external USB drive appears in the menu, not the new 500GB drive I just installed.

 

[stridemat]

If you put your old hard drive back into your mac, and put the new one in an enclosure then you should be able to boot into OSX and run disk utility and format the external drive. Now swap the drives round and you should all be good.

 

[randomlysid]

I tried that, formatted the new hard disk using my friend's mac and this time I tried booting off the old drive. I am still not detecting the new drive, even after formatting.
Any other ideas about what it could be? Is there any chance that formatting the hdd using 10.6 made it incompatible with the 10.4 disk utility? (I'm clutching at straws now).