August 9, 2012 by Volamoot at Mashable!
Virtually all machines running Windows 7 will be able to operate on Windows 8, which will be released in October. Apple’s OS X Mountain Lion, released July 25, runs on most Macs that can run Lion, but if your machine was made in 2007 or 2008, it might not be compatible.
Supported models include:
iMac (Mid 2007 or newer)
MacBook (Late 2008 Aluminum, or Early 2009 or newer)
MacBook Pro (Mid/Late 2007 or newer)
Xserve (Early 2009)
MacBook Air (Late 2008 or newer)
Mac mini (Early 2009 or newer)
Mac Pro (Early 2008 or newer)…
posted by Mashable from http://mashable.com/2012/08/08/is-your-laptop-too-old-for-mountain-lion-or-windows-8/