InstallAware

I'm installing on an XP Pro machine, and sitting in the debugger I see this sequence.
Set Variable ALLUSERS to TRUE
...
Get Folder Location System->Desktop Directory into DESKTOPDIR

Inspection of DESKTOPDIR shows "c:\\Documents and Settings\\qaadamin01\\Desktop"
Shouldn't this be for All Users? Is there a fix/work around for this anomaly?

Not all system variables have a value for all users. The all users flag is effective only when applicable.

From the documentation I understand that setting ALLUSERS to true, and querying the DESKTOPDIR variable should result in a directory like: c:\\documents and settings\\All Users\\Desktop. In this case certainly (XP Pro) such a directory does exist - I don't give the user the option to install only on one user's desktop.
I'm resorting to:
Set Persistent Variable ALLUSERS to TRUE

Get Exact OS Level into OperatingSystem
Get Folder Location System->Desktop Directory into DESKTOPDIR
if Variable DESKTOPDIR not Contains All Users
if Variable OperatingSystem Equals VISTA
Set Persistent Variable DESKTOPDIR to C:\\Users\\All Users\\Desktop
else
Set Persistent Variable DESKTOPDIR to C:\\Documents and Settings\\All Users\\Desktop
end
end

There is a check box in the call to Get Folder Location System->Desktop Directory into DESKTOPDIR "For all users". It was not checked.