Turned out I was wrong <g> and it was not GetSystemInfo() call.

Here is the code from Vladimir (originally from Alexander Golovlev, which is the same as yours with a registry check):

#define gREGKEYSYSINFO "SOFTWARE\Microsoft\Shared Tools\MSINFO" 
#define gREGVALSYSINFO "PATH" 
#define SW_NORMAL 1 

DECLARE LONG ShellExecute IN SHELL32.DLL ; 
LONG nWinHandle, STRING cOperation,; 
STRING cFileName, STRING cParameters,; 
STRING cDirectory, INTEGER nShowWindow 

Local lcSysInfoPath 

* Try To Get System Info Program Path\Name From Registry... 
oReg = NewObject("registry", "libs\registry.prg") 
lcSysInfoPath = oReg.ReadRegistryString(HKEY_LOCAL_MACHINE, gREGKEYSYSINFO, gREGVALSYSINFO) 

If ShellExecute(0, "open", lcSysInfoPath, "", "", SW_NORMAL) <= 32 
MessageBox("System Information Is Unavailable At This Time") 
endif

>I think the equivalent in Vista is systeminfo.exe...
>
>
>>>It's probably trying to find sysinfo.exe or something, which doesn't exist under the Vista anymore.
>>>
>>>Shouldn't be too hard to fix, IMO - an equivalent utility must exist in the Vista.
>>
>>Looks like you're right
>>Re: System Info Thread #872066 Message #872072
>>
>>Though AFAIK we used slightly different code. I'm going to check at home.