diff --git a/autotest/client_autotest.cc b/autotest/client_autotest.cc
index b884036..cc34ba4 100644
--- a/autotest/client_autotest.cc
+++ b/autotest/client_autotest.cc
@@ -8,16 +8,6 @@
 
 // -----------------------------------------------------------------------------
 
-#if (defined(_WIN32) || defined(_WIN64))
-// You need to set environment variable SSL_CERT_FILE properly to enable
-// SSL verification.
-bool kSslVerify = false;
-#else
-bool kSslVerify = true;
-#endif
-
-// -----------------------------------------------------------------------------
-
 // JSON helper functions (based on jsoncpp).
 
 // Parse a string to JSON object.
@@ -97,8 +87,6 @@ TEST(ClientTest, Get_Shortcut) {
 TEST(ClientTest, Get_SSL) {
   webcc::ClientSession session;
 
-  session.set_ssl_verify(kSslVerify);
-
   try {
     // HTTPS is auto-detected from the URL scheme.
     auto r = session.Request(webcc::RequestBuilder{}.Get().
diff --git a/examples/client_basics.cc b/examples/client_basics.cc
index 79beae4..192c74d 100644
--- a/examples/client_basics.cc
+++ b/examples/client_basics.cc
@@ -3,14 +3,6 @@
 #include "webcc/client_session.h"
 #include "webcc/logger.h"
 
-#if (defined(_WIN32) || defined(_WIN64))
-// You need to set environment variable SSL_CERT_FILE properly to enable
-// SSL verification.
-bool kSslVerify = false;
-#else
-bool kSslVerify = true;
-#endif
-
 static void PrintSeparator() {
   static const std::string s_line(80, '-');
   std::cout << s_line << std::endl;
@@ -21,8 +13,6 @@ int main() {
 
   webcc::ClientSession session;
 
-  session.set_ssl_verify(kSslVerify);
-
   try {
     PrintSeparator();
 
diff --git a/examples/file_upload_client.cc b/examples/file_upload_client.cc
index 5cb37f8..8c67be9 100644
--- a/examples/file_upload_client.cc
+++ b/examples/file_upload_client.cc
@@ -5,14 +5,6 @@
 #include "webcc/client_session.h"
 #include "webcc/logger.h"
 
-#if (defined(_WIN32) || defined(_WIN64))
-// You need to set environment variable SSL_CERT_FILE properly to enable
-// SSL verification.
-bool kSslVerify = false;
-#else
-bool kSslVerify = true;
-#endif
-
 void Help(const char* argv0) {
   std::cout << "Usage: " << argv0 << " <upload_dir> [url]" << std::endl;
   std::cout << "Default Url: http://httpbin.org/post" << std::endl;
diff --git a/examples/github_client.cc b/examples/github_client.cc
index 44d648f..e6954e0 100644
--- a/examples/github_client.cc
+++ b/examples/github_client.cc
@@ -10,14 +10,6 @@
 // Change to 1 to print response JSON.
 #define PRINT_RESPONSE 0
 
-#if (defined(_WIN32) || defined(_WIN64))
-// You need to set environment variable SSL_CERT_FILE properly to enable
-// SSL verification.
-bool kSslVerify = false;
-#else
-bool kSslVerify = true;
-#endif
-
 const std::string kUrlRoot = "https://api.github.com";
 
 // -----------------------------------------------------------------------------
@@ -136,8 +128,6 @@ int main() {
 
   webcc::ClientSession session;
 
-  session.set_ssl_verify(kSslVerify);
-
   ListEvents(session);
 
   return 0;
diff --git a/webcc/socket.cc b/webcc/socket.cc
index 6ae3b84..ffca6a6 100644
--- a/webcc/socket.cc
+++ b/webcc/socket.cc
@@ -1,5 +1,17 @@
 #include "webcc/socket.h"
 
+#if WEBCC_ENABLE_SSL
+#if (defined(_WIN32) || defined(_WIN64))
+
+#include <windows.h>
+#include <wincrypt.h>
+#include <cryptuiapi.h>
+
+#include "openssl/x509.h"
+
+#endif  // defined(_WIN32) || defined(_WIN64)
+#endif  // WEBCC_ENABLE_SSL
+
 #include "boost/asio/connect.hpp"
 #include "boost/asio/read.hpp"
 #include "boost/asio/write.hpp"
@@ -38,14 +50,56 @@ void Socket::Close(boost::system::error_code* ec) {
 
 #if WEBCC_ENABLE_SSL
 
+#if (defined(_WIN32) || defined(_WIN64))
+
+// See: https://stackoverflow.com/a/40046425/6825348
+static bool UseSystemCertificateStore(SSL_CTX* ssl_ctx) {
+  // NOTE: Cannot use nullptr to replace NULL.
+  HCERTSTORE cert_store = ::CertOpenSystemStoreW(NULL, L"ROOT");
+
+  if (cert_store == nullptr) {
+    LOG_ERRO("Cannot open Windows system certificate store.");
+    return false;
+  }
+
+  X509_STORE* x509_store = SSL_CTX_get_cert_store(ssl_ctx);
+  PCCERT_CONTEXT cert_context = nullptr;
+
+  while (cert_context = CertEnumCertificatesInStore(cert_store, cert_context)) {
+    auto in = (const unsigned char **)&cert_context->pbCertEncoded;
+    X509* x509 = d2i_X509(nullptr, in, cert_context->cbCertEncoded);
+
+    if (x509 != nullptr) {
+      if (X509_STORE_add_cert(x509_store, x509) == 0) {
+        LOG_ERRO("Cannot add Windows root certificate.");
+      }
+
+      X509_free(x509);
+    }
+  }
+
+  CertFreeCertificateContext(cert_context);
+  CertCloseStore(cert_store, 0);
+
+  return true;
+}
+
+#endif  // defined(_WIN32) || defined(_WIN64)
+
 namespace ssl = boost::asio::ssl;
 
 SslSocket::SslSocket(boost::asio::io_context& io_context, bool ssl_verify)
     : ssl_context_(ssl::context::sslv23),
       ssl_socket_(io_context, ssl_context_),
       ssl_verify_(ssl_verify) {
+#if (defined(_WIN32) || defined(_WIN64))
+  if (ssl_verify_) {
+    UseSystemCertificateStore(ssl_context_.native_handle());
+  }
+#else
   // Use the default paths for finding CA certificates.
   ssl_context_.set_default_verify_paths();
+#endif  // defined(_WIN32) || defined(_WIN64)
 }
 
 void SslSocket::Connect(const std::string& host, const Endpoints& endpoints,