This is how I did it.
public static bool IsLocal(DirectoryInfo dir)
{
foreach (DriveInfo d in DriveInfo.GetDrives())
{
if (string.Compare(dir.Root.FullName, d.Name, StringComparison.OrdinalIgnoreCase) == 0) //[drweb86] Fix for different case.
{
return (d.DriveType != DriveType.Network);
}
}
throw new DriveNotFoundException();
}