Does your computer support Hyper-V ? If it doesn't, then you can't run the emulator on your machine. According to the below Microsoft link,
Your computer’s BIOS must support the following requirements, and they must be enabled: Hardware-assisted virtualization. Second Level Address Translation (SLAT). Hardware-based Data Execution Prevention (DEP)."
http://msdn.microsoft.com/en-us/library/windowsphone/develop/ff626524%28v=vs.105%29.aspx#hyperv