Get installed software list using C#

Source from : http://social.msdn.microsoft.com/Forums/en-US/94c2f14d-c45e-4b55-9ba0-eb091bac1035/c-get-installed-programs

The solution is to search for 3 places in registry:

1. SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall inside CurrentUser
2. SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall inside LocalMachine
3. SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall in LocalMachine

the code below suits you needs.

public static bool IsApplicationInstalled(string p_name)
{
    string displayName;
    RegistryKey key;

    // search in: CurrentUser
    key = Registry.CurrentUser.OpenSubKey(@"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall");
    foreach (String keyName in key.GetSubKeyNames())
    {
        RegistryKey subkey = key.OpenSubKey(keyName);
        displayName = subkey.GetValue("DisplayName") as string;
        if (p_name.Equals(displayName, StringComparison.OrdinalIgnoreCase) == true)
        {
            return true;
        }
    }

    // search in: LocalMachine_32
    key = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall");
    foreach (String keyName in key.GetSubKeyNames())
    {
        RegistryKey subkey = key.OpenSubKey(keyName);
        displayName = subkey.GetValue("DisplayName") as string;
        if (p_name.Equals(displayName, StringComparison.OrdinalIgnoreCase) == true)
        {
            return true;
        }
    }

    // search in: LocalMachine_64
    key = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall");
    foreach (String keyName in key.GetSubKeyNames())
    {
        RegistryKey subkey = key.OpenSubKey(keyName);
        displayName = subkey.GetValue("DisplayName") as string;
        if (p_name.Equals(displayName, StringComparison.OrdinalIgnoreCase) == true)
        {
            return true;
        }
    }

    // NOT FOUND
    return false;
}

It seems you now have to use OpenBaseKey, there is the code im using:

List<string> gInstalledSoftware
        void GetInstalledSoftwareList()
        {
            string displayName;

            using (RegistryKey key = Registry.CurrentUser.OpenSubKey(@"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall", false))
            {                
                foreach (String keyName in key.GetSubKeyNames())
                {
                    RegistryKey subkey = key.OpenSubKey(keyName);
                    displayName = subkey.GetValue("DisplayName") as string;
                    if (string.IsNullOrEmpty(displayName))
                        continue;

                    gInstalledSoftware.Add(displayName.ToLower());
                }
            }

            //using (RegistryKey key = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall", false))
            using (var localMachine = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry64))
            {
                var key = localMachine.OpenSubKey(@"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall", false);
                foreach (String keyName in key.GetSubKeyNames())
                {
                    RegistryKey subkey = key.OpenSubKey(keyName);
                    displayName = subkey.GetValue("DisplayName") as string;
                    if (string.IsNullOrEmpty(displayName))
                        continue;

                    gInstalledSoftware.Add(displayName.ToLower());
                }
            }

            using (var localMachine = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry32))
            {
                var key = localMachine.OpenSubKey(@"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall", false);
                foreach (String keyName in key.GetSubKeyNames())
                {
                    RegistryKey subkey = key.OpenSubKey(keyName);
                    displayName = subkey.GetValue("DisplayName") as string;
                    if (string.IsNullOrEmpty(displayName))
                        continue;

                    gInstalledSoftware.Add(displayName.ToLower());
                }
            }

            using (RegistryKey key = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall",false))
            {
                foreach (String keyName in key.GetSubKeyNames())
                {
                    RegistryKey subkey = key.OpenSubKey(keyName);
                    displayName = subkey.GetValue("DisplayName") as string;
                    if (string.IsNullOrEmpty(displayName))
                        continue;

                    gInstalledSoftware.Add(displayName.ToLower());
                }
            }             
        }