I have an MBP 3,1 (Mid-late 2007 model) and I'm trying to reinstall Snow Leopard. I don't have the original discs with my Mac, I got an original Snow Leopard install disc from another MacBook Pro but when I try to install says "Mac OS X cannot be installed on this computer".
Is there any way to re-install Snow Leopard on my machine?
The discs that come with a Mac are custom to that model (at least they used to be). If the other MBP isn't a 3,1 model then the install can fail like you experienced.
If the two machines are the same model, it might be that the other discs are upgrade only, and require an existing OS X installation before the upgrade can proceed (I had this problem with a MacBook that came with Tiger DVDs and Leopard upgrade DVDs as Leopard was just out - you had to install Tiger first, then upgrade to Leopard).
The discs that come with a specific Mac are specific to that model of computer and won't work in another Mac. Your original discs would have come with either Mac OS X 10.4.9 (Tiger) or Mac OS X 10.5 (Leopard) depending on when in 2007 you purchased it.
If you don't have the original discs for your Mac you'll have to pick up a copy of Snow Leopard (~$30 USD) from your local Apple retailer or you can contact Apple for a replacement copy of your discs (unsure how much but I'd suspect about the same price) if you don't want Snow Leopard.
Once you have the disc it's just a matter of putting it in and installing.
