In Windows 8, Microsoft has discontinued Windows XP mode. Therefore, if you are accustomed to running applications on the XP Mode VM, you will have to use another virtualization technology such as Hyper-V or VMware Player/Workstation.
I happen to have Hyper-V installed for a Windows Phone 8 SDK and VMware installed with a bunch of guest OS VM's. After installing Hyper-V, I am no longer able to power on the guest VM's running in VMware.
I found this article of a workaround, which is essentially disabling Hyper-V so that VMware can run: http://forums.mydigitallife.info/threads/43761-VMware-and-Hyper-V-not-compatible.
Here are the steps:
- Open Hyper-V manager and "stop service" on the right panel,
- Then at an elevated command prompt, run the following command:
bcdedit /set hypervisorlaunchtype off
This will disable Hyper-v at an elevated command prompt
To enable Hyper-v to use Hyper-V again, at an elevated command prompt, type:
bcdedit /set hypervisorlaunchtype auto
You must reboot in order for changes to take effect.
Here is another great link on the topic: http://jorgequestforknowledge.wordpress.com/2012/05/26/using-both-microsoft-hyper-v-and-vmware-workstation-on-the-same-machine/.