I have the Hyper-V role enabled on Windows 8.1 for VS Express Windows Phone Emulation. The problem is this error when I try to run a VMWare Player virtual machine:
VMware Player and Hyper-V are not compatible. Remove the Hyper-V role from the system before running VMware Player.
The workaround is to disable Hyper-V so that you can use VMWare.
To do this open an Administrator Command Prompt, enter this command and then reboot:
bcdedit /set hypervisorlaunchtype off
Hyper-V can be enabled again with this command (which also requires a reboot):
bcdedit /set hypervisorlaunchtype auto