如果文件名放置到目录不起作用

我有小问题。。。我编码自动更新程序，当我下载.exe文件时，我想把它放在主目录…和其他扩展到子目录.

File.exe=这是我下载到主目录的位置Else=放置到子目录…但不起作用，将所有内容放置到主目录

if(ex[1] == "File.exe")
{
    if (File.Exists(path))
    {
        if(File.Exists(String.Format("{0}WoW.exe", wow.GetValue("InstallPath").ToString())))
        {
            File.Copy(String.Format("{0}WoW.exe", wow.GetValue("InstallPath").ToString()), String.Format("{0}WoW_zaloha_Awrodar_old_file.exe", wow.GetValue("InstallPath").ToString()), false);
            File.Delete(String.Format("{0}WoW.exe", wow.GetValue("InstallPath").ToString()));
        }
        else if(File.Exists(String.Format("{0}Wow.exe", wow.GetValue("InstallPath").ToString())))
        {
            File.Copy(String.Format("{0}Wow.exe", wow.GetValue("InstallPath").ToString()), String.Format("{0}Wow_zaloha_Awrodar_old_file.exe", wow.GetValue("InstallPath").ToString()), false);
            File.Delete(String.Format("{0}Wow.exe", wow.GetValue("InstallPath").ToString()));
        }
        FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read);
        MD5 md5 = new MD5CryptoServiceProvider();
        byte[] retVal = md5.ComputeHash(fs);
        fs.Close();
        StringBuilder sb = new StringBuilder();
        foreach(byte b in retVal)
            sb.Append(string.Format("{0:X2}", b));
        if(ex[2] == sb.ToString())
            proceed = false;
    }
}
else
{
    if(File.Exists(MPQpath))
    {
        FileStream fs = new FileStream(MPQpath, FileMode.Open, FileAccess.Read, FileShare.Read);
        MD5 md5 = new MD5CryptoServiceProvider();
        byte[] retVal = md5.ComputeHash(fs);
        fs.Close();
        StringBuilder sb = new StringBuilder();
        foreach(byte b in retVal)
            sb.Append(string.Format("{0:X2}", b));
        if(ex[2] == sb.ToString())
            proceed = false;
    }
}