C#中判断某软件是否已安装

private void button1_Click(object sender, EventArgs e)   
{   
    if (checkAdobeReader() == true)   
    {   
        MessageBox.Show("有安裝 Adobe Reader ");   
    }   
    else  
    {   
        MessageBox.Show("沒有安裝 Adobe Reader ");   
    }   
}   
/// <summary>   
/// 確認是否有安裝 Adobe Reader    
/// </summary>   
/// <returns>true: 有安裝, false:沒有安裝</returns>   
private bool checkAdobeReader()   
{   
    Microsoft.Win32.RegistryKey uninstallNode = Microsoft.Win32.Registry.LocalMachine.OpenSubKey(@"SOFTWARE/Microsoft/Windows/CurrentVersion/Uninstall");   
    foreach (string subKeyName in uninstallNode.GetSubKeyNames())   
    {   
        Microsoft.Win32.RegistryKey subKey = uninstallNode.OpenSubKey(subKeyName);   
        object displayName = subKey.GetValue("DisplayName");   
        if (displayName != null)   
        {   
            if (displayName.ToString().Contains("Adobe Reader"))   
            {   
                return true;   
                // MessageBox.Show(displayName.ToString());   
            }   
        }   
    }   
    return false;   
}