Kd.exe commands not working - "has no export"

Question

I'm looking for some help figuring out why commands I've used in the past with windbg and kd are no longer working. I'm not a kd wiz and I'm sure I'm missing setup somewhere, or I'm neglecting a step, but I can't figure out what I'm missing.  
I'm using a customer supplied full kernel memory dump as I have in the past, but when I try the command
"!mem" instead of my memory usage, I get the error
"No export mem found". When I try "!objects" I get a similar error "No export objects found".  Even "!findstack mysymbol" gives the error
"No export findstack found".  What am I missing? 
Here's my kd startup command line:
kd.exe  -v -y c:\path\to\my\symbols -z c:\path\to\memory.dmp
My kd.exe version is "6.3.9600.17298 AMD64"

Answer 1

'!<cmd>' are extension commands:
Using Debugger Extension Commands
http://msdn.microsoft.com/en-us/library/windows/hardware/ff560098(v=vs.85).aspx
Kernel-Mode Extensions
http://msdn.microsoft.com/en-us/library/windows/hardware/ff551891(v=vs.85).aspx
Besides, !findstack is 'user mode':
User-Mode Extensions
http://msdn.microsoft.com/en-us/library/windows/hardware/ff560035(v=vs.85).aspx
Useful commands:
.chain (List Debugger Extensions)
http://msdn.microsoft.com/en-us/library/windows/hardware/ff562212(v=vs.85).aspx
.load, .loadby (Load Extension DLL)
http://msdn.microsoft.com/en-us/library/windows/hardware/ff563964(v=vs.85).aspx
With MS extension-dlls
!<module>.help
should give a short overview.
With kind regards