As per the comments on your question, I'll explain:
You can perform Windows Phone 8.x development on Windows 7 or later provided you have a physical device, however if you want to use the Windows Phone 8.x emulators then you need to have Hyper-V available, this is because the WP8 emulators run as Hyper-V virtual-machines, side-by-side with your main operating system.
Therefore, to use the WP8 emulators you must be running Windows 8 Pro, Windows 8 Enterprise or Windows Server 2012 (or later, e.g. Windows 8.1 Pro). The standard "Home edition" of Windows 8 does not include Hyper-V. Read up about Client Hyper-V on TechNet.
Hyper-V requires hardware virtualisation and, as an accelerated platform with hardware requirements, will not run within another virtualiser (this is in contrast to how you can run VirtualBox or VirtualPC under Hyper-V). You must be running Windows 8 Pro as your "root" operating system.