Q: While trying to enable Hyper-V on my Windows 8 computer, why does it say my processor doesn't have Secondary Level Address Translation (SLAT), when Coreinfo says it does?

A: Although Secondary Level Address Translation (SLAT) is optional for server Hyper-V unless RemoteFX is used, it's mandatory on client computers. (See also, "Becoming un-confused about Hyper-V, Windows 8, and SLAT").

That's because the assumption is that with a client device, advanced graphics capabilities will always be present, which necessitates SLAT. If a Hyper-V feature is enabled on a Windows 8 client, a check is done. If SLAT isn't performed, the feature can't be installed and a message is displayed (Figure 1).

Message that shows when SLAT is not present

Running the SysInternals coreinfo tool with the -v switch can confirm the presence of SLAT:

C:>coreinfo -v 

When I ran it, this is the output I got:

Coreinfo v3.04 - Dump information on system CPU and memory topology
Copyright (C) 2008-2012 Mark Russinovich
Sysinternals - www.sysinternals.com

Intel(R) Core(TM)2 Duo CPU P9600 @ 2.66GHz
Intel64 Family 6 Model 23 Stepping 10, GenuineIntel
HYPERVISOR - Hypervisor is present
VMX * Supports Intel hardware-assisted virtualization
EPT - Supports Intel extended page tables (SLAT)

Note that the output isn't showing SLAT is present. A "-" means the feature is missing while a "*" means it's present. The output shows that this machine has a processor that doesn't support SLAT, and therefore can't have the client Hyper-V feature installed. 

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