Check if application is installed in registry

Question

Right now I use this to list all the applications listed in the registry for 32bit & 64. I have seen the other examples of how to check if an application is installed wi

Answer 1

I have checked @Stellan Lindell's code and it doesn't work in all cases. My version should work in all scenarios and checks the specific version of installed programs(x86, x64).

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Win32;

namespace Test
{  
internal class Program
{  
    public enum ProgramVersion
    {
        x86,
        x64
    }

    private static IEnumerable GetRegisterSubkeys(RegistryKey registryKey)
    {
        return registryKey.GetSubKeyNames()
                .Select(registryKey.OpenSubKey)
                .Select(subkey => subkey.GetValue("DisplayName") as string);
    }

    private static bool CheckNode(RegistryKey registryKey, string applicationName, ProgramVersion? programVersion)
    {
        return GetRegisterSubkeys(registryKey).Any(displayName => displayName != null
                                                                  && displayName.Contains(applicationName)
                                                                  && displayName.Contains(programVersion.ToString()));
    }

    private static bool CheckApplication(string registryKey, string applicationName, ProgramVersion? programVersion)
    {
        RegistryKey key = Registry.LocalMachine.OpenSubKey(registryKey);

        if (key != null)
        {
            if (CheckNode(key, applicationName, programVersion))
                return true;

            key.Close();
        }

        return false;
    }

    public static bool IsSoftwareInstalled(string applicationName, ProgramVersion? programVersion)
    {
        string[] registryKey = new [] {
            @"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall",
            @"SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall"
        };

        return registryKey.Any(key => CheckApplication(key, applicationName, programVersion));
    }

    private static void Main()
    {
        // Examples
        Console.WriteLine("Notepad++: " + IsSoftwareInstalled("Notepad++", null));
        Console.WriteLine("Notepad++(x86): " + IsSoftwareInstalled("Notepad++", ProgramVersion.x86));
        Console.WriteLine("Notepad++(x64): " + IsSoftwareInstalled("Notepad++", ProgramVersion.x64));
        Console.WriteLine("Microsoft Visual C++ 2009: " + IsSoftwareInstalled("Microsoft Visual C++ 2009", null));
        Console.WriteLine("Microsoft Visual C-- 2009: " + IsSoftwareInstalled("Microsoft Visual C-- 2009", null));
        Console.WriteLine("Microsoft Visual C++ 2013: " + IsSoftwareInstalled("Microsoft Visual C++ 2013", null));
        Console.WriteLine("Microsoft Visual C++ 2012 Redistributable (x86): " + IsSoftwareInstalled("Microsoft Visual C++ 2013", ProgramVersion.x86));
        Console.WriteLine("Microsoft Visual C++ 2012 Redistributable (x64): " + IsSoftwareInstalled("Microsoft Visual C++ 2013", ProgramVersion.x64));
        Console.ReadKey();
    }
}
}