I currently have an acer laptop which I use as my primary computer, which runs windows 7. I also have a MBP which has Mac OS Leopard and Windows XP. Is there any software I can buy that will allow me to use the Acer as my primary computer and the Mac as the secondary monitor? Do both computers have to have the same operating system? I want to use both in my home office, and save money by not having to buy external monitors. Thanks!