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We've had the same question about Quickbooks from several of our other members.

What I have previously recommended since it's only one app you wish to run, is to use virtual software. In other words, run a virtual copy of Windows using a VM (virtual machine). Doing it this way does not require a reboot or re-partitioning of the hard drive.
I recommend using the free virtual software from Oracle -
VirtualBox. You do, however, need a legal copy of Windows to install to the virtual machine so you can install QB. Other virtual software is expensive = Parallels, and Fusion. (both are around $70 and you still need Windows)
Other methods of running QB would be to use Boot Camp and setup a dual boot. That means partitioning the hard drive and having to reboot every time you wish to boot Windows in order to run QB. Another method would be to use an application called CrossOver which can simulate a Windows environment in order to run QB. However, this method can be expensive since you also have to buy CrossOver in addition to Windows and there is no guaranty that QB will run.