This c# code shows the versions of the .NET framework installed on a PC.

 

private void button2_Click(object sender, EventArgs e) 
{
 
string key1 = "";
string key2 = "";
string key3 = "";
bool v10 = false;
bool v11 = false;
bool v20 = false;

key1 = Registry.LocalMachine.OpenSubKey("SOFTWARE").OpenSubKey("Microsoft").OpenSubKey(".NETFramework").OpenSubKey("Policy").OpenSubKey("v1.0").GetValue("3705").ToString();

key2 = Registry.LocalMachine.OpenSubKey("SOFTWARE").OpenSubKey("Microsoft").OpenSubKey(".NETFramework").OpenSubKey("Policy").OpenSubKey("v1.1").GetValue("4322").ToString();

key3 = Registry.LocalMachine.OpenSubKey("SOFTWARE").OpenSubKey("Microsoft").OpenSubKey(".NETFramework").OpenSubKey("Policy").OpenSubKey("v2.0").GetValue("50727").ToString();

v10 = (key1 == "3321-3705"); 
v11 = (key2 == "3706-4322"); 
v20 = (key3 == "50727-50727");
MessageBox.Show(".Net Framework v1.0 – " + v10.ToString() + Environment.NewLine +
".Net Framework v1.1 – " + v11.ToString() + Environment.NewLine +
".Net Framework v2.0 – " + v20.ToString());
        }