Mac BOOT LOOP!

I'm formatting my iMac 21' late/early 2008 (Not sure)

Formatted it with OS X Leopard, with the original disk that came with the Mac.

It was working perfectly, until I installed the software updates. It's now stuck in a constant boot. The white apple screen with the grey apple and the grey pinwheel. I've left it for hours and it doesn't boot at all.

There is absolutely NO way I could possibly have access to a firewire and another Mac, so that's off the cards.

Yes, I have tried every single boot command that exists. And i'm 99% sure that it's not a failed logic board/HDD.

The boot commands COULD be that the keyboard I am using doesnt function under the startup of the Mac, but it does work when the Mac (used to) boots.

I'm unsure if I have access to another keyboard, but i'll check if I can borrow one for the time being. (Possibly tommorow)

Could this be the cause????


Any help to get out of this loop would be appricitated. I don't really know where else to post.

Thanks!

 

I would.. but Boot commands are not working

As I said before, it could be the keyboard. Will update tommorow.