Macbook HELP!!!

This is such a longer story of how thins happened but I'll try and keep it to the point as best I can. Firstly I'd like to point out that I am not very technically minded (as will become apparent). Sorry if this is in the wrong forum bit too.

My Macbook was having some issue with the hard drive being corrupt and it said the best way to fix was to format the drive and reinstall OS X.

I backed up my stuff (pics,dvd,docs etc and Yes, I know now that I was meant to do a time machine type back up of the whole system) and reformatted the drive in the MAC OS (journalled) [I think that's what it was called] and I inserted the OS X Snow Leopard disks and was met by the error "MAC OS X can not be installed on this machine". I don't see why this wouldn't work as I had Snow Leopard on there to start with, so with Snow Leopard not working I tried to install Leopard, again same error.

Now my pal has installed windows on the macbook by formatting the hard drive to NTFS [again, I think this is right, all the right letters anyway, not to sure on the order].

How do I get rid of windows and get my mac back to being a mac?

Please Help!!!

Get the original discs that came with the machine, not the discs that came with someone else's machine. If you have lost them, you can call Apple and ask for a set of replacement discs.

If your Mac did not have Snow Leopard as the original OS, then you could also purchase a retail copy of SL. This "assumes" you are correct that you had SL installed, which means you have an Intel Mac, since you have not supplied the info regarding your system.