Today users are using lots of 3rd party apps to have multiple OS in the system but now no more needed as Microsoft brings Hyper-V technology to Windows. In Windows 8 we will see Hyper-V so that you can run more than one Operating System on a single machine inside a virtual machine (VM).
What is Hyper-V: It requires a 64-bit system that has Second Level Address Translation (SLAT). SLAT is a feature present in the current generation of 64-bit processors by Intel & AMD. You’ll also need a 64-bit version of Windows 8, and at least 4GB of RAM. Hyper-V does support creation of both 32-bit and 64-bit operating systems in the VMs.