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;  
}