Normally when you want to install Hyper-V on Windows 8 inside VMware Workstation 8/Fusion 4 you will get the following message:
Hyper-V cannot be installed: A hypervisor is already running.
1. Shutdown the machine and edit the Virtual Machine Settings > Hardware > Processors > check the “Virtualize Intel VT-x/EPT” (Note: Your processor must 64bit supported)
2. Edit the vmx file of the Windows 8 VMware virtual machine and add the setting “hypervisor.cpuid.v0 = “FALSE”
add one line.
mce.enable = “TRUE”
With this line added to your VMX file, you no longer get the HAL_Memory_Allocation error.