In Windows Vista and 7, I can't access the %DEFAULTUSERPROFILE% system variable - it shows as not found

Question

If I try to access this system variable from the Run... dialog, Windows tells me the directory doesn't exist. Some system variables, like %SYSTEMROOT% and %USERPROFILE%, do work. Consequently, if I try to use a supposedly nonexistent variable like %DEFAULTUSERPROFILE% or %PROFILESFOLDER% in C#, I get nothing in return. Is there something special I need to do to get access to these variables?

Answer 1

Have you tried %ALLUSERSPROFILE%?

Answer 2

My suggestion is to retreive that value directly from the registry - in case you can't expand it:

public static string GetDefaultUserProfilePath() {
    string path = System.Environment.GetEnvironmentVariable("DEFAULTUSERPROFILE") ?? string.Empty;
    if (path.Length == 0) {
        using (Microsoft.Win32.RegistryKey key = Microsoft.Win32.Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList")) {
            path = (string)key.GetValue("Default", string.Empty);
        }
    }
    return path;
}

Answer 3

You mention C# - you can't use environment variables inside C# path strings, you need to replace them using System.Environment.

System.Environment.GetEnvironmentalVariable("USERPROFILE");

I haven't seen %DefaultUserProfile% before - should it point to the first username that was installed?

Answer 4

I need to point to C:\Users\Default\AppData.

Are you sure? Be aware that this folder is used to populate the inital AppData directory for each new user added to the system.

If you want the actual shared application data directory in .NET, it's this:

String commonAppData = Environment.GetFolderPath(Environment.SpecialFolders.CommonApplicationData)

Answer 5

Call SHGetFolderLocation with CSIDL_PROFILE and -1 as the token parameter