Get .NET Framework version

Check .NET Framework versions
This class has two functions. One gets you the latest version installed. The other one returns a boolean

based on whether a specific version is installed or not.

public class NETVersionChecker
{
    public struct DOTNETVersionInfo
    {
        public double FrameworkVersion;

        public int ServicePack;

    }
    public static bool CheckRequiredDOTNETVersion(DOTNETVersionInfo required)
    {
        bool reslt = false;

        double tmpFramework = 0;

        int tmpSP = 0;

        try
        {
            RegistryKey installed_versions = Registry.LocalMachine.OpenSubKey

            (@"SOFTWARE\Microsoft\NET Framework Setup\NDP", false);

            string[] version_names = installed_versions.GetSubKeyNames();

            string tmpBaseVersion;

            //check each installed version
            foreach (string ver in version_names)
            {
                //set default values
                tmpFramework = 0;

                tmpSP = 0;

                tmpBaseVersion = string.Empty;

                try
                {
                    //version names start with 'v', eg, 'v3.5' which needs to be

                     trimmed off before conversion
                    string tmpFullVersion = ver.Remove(0, 1);

                    //now remove the minor versions 2.0.5725
                    if (tmpFullVersion.Length > 3)
                    {
                        tmpBaseVersion = tmpFullVersion.Remove(tmpFullVersion.IndexOfAny

                               ((".").ToCharArray(), 2), tmpFullVersion.Length - 3);

                    }
                    else //its just 3 digit version
                    {
                        tmpBaseVersion = tmpFullVersion;

                    }
                    double basicVersion = 0;

                    if (double.TryParse(tmpBaseVersion, out basicVersion))
                    {
                        tmpFramework = basicVersion;

                    }
                }
                catch
                {
                    tmpFramework = 0;

                }
                //The service pack key might not exist so it might throw an error
                try
                {
                    tmpSP = Convert.ToInt32(installed_versions.OpenSubKey(ver)

                       .GetValue("SP", 0));

                }
                catch { }
                if (tmpFramework == required.FrameworkVersion && tmpSP

                    == required.ServicePack)
                {
                    reslt = true;

                    break;

                }
            }
        }
        catch (Exception exp)
        {
            string message = "Error occured:" + exp.Message;

            if (exp is System.Security.SecurityException)
            {
                message += "\n Unable to find .NET Framework version. \n The user does

                  not have the permissions required to access the registry key:\n"

                   + @"HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP";

            }
            MessageBox.Show(message);

        }
        return reslt;

    }
    public static DOTNETVersionInfo GetLatestDOTNETVersion()
    {
        DOTNETVersionInfo dnVer;

        dnVer.FrameworkVersion = 0;

        dnVer.ServicePack = 0;

        try
        {
            RegistryKey installed_versions = Registry.LocalMachine.OpenSubKey

               (@"SOFTWARE\Microsoft\NET Framework Setup\NDP", false);

            string[] version_names = installed_versions.GetSubKeyNames();

            //version names start with 'v', eg, 'v3.5' which needs to be trimmed off

               before conversion
            double Framework = Convert.ToDouble(version_names[version_names.Length - 1]

                               .Remove(0, 1), CultureInfo.InvariantCulture);

            dnVer.FrameworkVersion = Framework;

            //The service pack key might not exist so it might throw an error
            int SP = 0;

            try
            {
                SP = Convert.ToInt32(installed_versions.OpenSubKey(version_names

                                        [version_names.Length - 1]).GetValue("SP", 0));

            }
            catch { }
            dnVer.ServicePack = SP;

        }
        catch(Exception exp)
        {
            string message = "Error occured:" + exp.Message;

            if (exp is System.Security.SecurityException)
            {
                message += "\n Unable to find .NET Framework version. \n The user does

                         not have the permissions required to access the registry key:\n"

                        + @"HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP";

            }
            MessageBox.Show(message);

        }
        return dnVer;

    }