Hi, some time ago i bought a mac pro without hard drive or install discs. I would like to know how can i install the OS on this computer, i dont have other mac os system, so i would like to know how to do it with a windows computer.
I installed it a new hard drive.
Unfortunately the 2008 MacBook Pro does not have the internet recovery feature. Your best bet honestly is to buy a USB drive that already has the installer for the version of OSX you want. I recommend El Capitan as that one for sure works on that model as I have one myself. Or you have to find the OSX image yourself and then do a bunch of stuff to be able to create the install USB from a Windows machine.
Then you just boot to the install drive, format the new hard drive, and install OSX. There are lots of guides out there so I won't link to them but just search "Formatting Mac drive using Disk Utility" and "Installing Mac OSX from USB".