It looks like incorrect type is passed as the first parameter. Casting the value with BITOR fixes the problem.

#include registry.h
#UNDEFINE HKEY_CLASSES_ROOT
#DEFINE HKEY_CLASSES_ROOT BITOR(0x80000000,0)
cRetVal = ""
oReg = GetObject("winmgmts:{impersonationLevel=impersonate}!\\.\root\default:StdRegProv")
cKeyPath = "dataproc.processor\CLSID"
iErrNo = oReg.GetStringValue( HKEY_CLASSES_ROOT, @cKeyPath , "", @cRetVal )

>Arrgh. Still grinding my teeth. What I am trying to do is get the GUID of a COM object so I can explore it programatically. So I make the WMI call to read the Registry for it, but there is no value name. So my code is still exploding.
>
>

>#include registry.h
>Local cRetVal as String
>Clear
>oRegRead = GetObject("winmgmts:{impersonationLevel=impersonate}!\\.\root\default:StdRegProv")
>cKeyPath = "dataproc.processor\CLSID"
>iErrNo = oRegRead.GetStringValue( HKEY_CLASSES_ROOT, cKeyPath , , @cRetVal )
>? cKeyPath
>? cRetVal
>? iErrNo
>

>
>It explodes I think on the value between cKeyPath and @cRetVal. I have tried putting in .Null. , Chr(0) , "" , " ", and ,, and it always blows up. How to address that?
>
>Thanks.