private void CertificateList_OnInitialized(object sender, EventArgs e) { string[] files = Directory.GetFiles("data/certs/", "*.p12"); X509Store store = new X509Store(StoreName.Root, StoreLocation.LocalMachine); store.Open(OpenFlags.MaxAllowed); foreach (var x in files) { var certificate = new X509Certificate2(File.ReadAllBytes(x), ""); var li = new CertListItem(Path.GetFileNameWithoutExtension(x), certificate); if (certificate.Thumbprint != null) { X509Certificate2Collection certs = store.Certificates.Find(X509FindType.FindByThumbprint, certificate.Thumbprint, true); li.Installed = certs.Count > 0; CertListBox.Items.Add(li); } } store.Close(); }