If you’ve recently downloaded the Windows 8 Developer Preview and tried to install it on VMware Workstation, VMware player, or VMware Fusion, you may have received the error:

*** VMware Workstation internal monitor error ***
vcpu-0:NOT_IMPLEMENTED vmcore/vmm/intr/apic.c:1903
Please report this problem by selecting menu item Help > VMware on the Web > Request Support, or by going to the Web page …

I can’t confirm this, but some have speculated that the message means that the version of the VMware product you are using (including VMware Workstation 7) does not support ACPI 2.0 which is required for Windows 8.
Regardless, the solution is to upgrade to VMware Workstation 8 or VMware Fusion 4. Alternatively, you can install Windows 8 within Oracle (Sun) VirtualBox 4.1.2. Make sure to use at least version 4.1.2 as older versions of VirtualBox do not work. VirtualBox and VMware Workstation can coexist on the same host.