Apple Hardware Test

My Intel iMac came with Leopard, which I used until Snow Leopard came out. I bought the Snow Leopard disc as soon as it was available and, over time, through software updates arrived at version 10.6.8.

Having had to get the hard drive replaced recently, it has occurred to me that out of curiosity I might use the Apple Hardware Test to have a look and see what it does. Of course, it's no longer on my system, because, having originally been installed with Leopard, it disappeared when I upgraded to SL. The new HD has a fresh install of SL. I can't boot into it by holding down the 'D' key upon reboot.

I have the original grey Leopard install discs that came with my machine, and see that disc 1 includes AHT version 3A137.

I have a copy of Pacifist.

So my questions are :

(a) Which file would I look for on disc 1?

(b) Assuming I can extract it, would it be in order to place it in the System/Library/Coreservices/.diagnostics folder (which after much reading on my part is as close as I get)?

(c) This might seem a trivial question, but I understand now that this AHT is machine specific, so should I then be able to reboot holding down the 'D' key and run the AHT?

New ground for me - all of this.

The machine's specs are :

Model Identifier: iMac7,1

Processor Name: Intel Core 2 Duo

Processor Speed: 2.4 GHz

Number Of Processors: 1

Total Number Of Cores: 2

L2 Cache: 4 MB

Memory: 4 GB

Bus Speed: 800 MHz