diff --git a/runtime/bin/ffi_test_functions.cc b/runtime/bin/ffi_test_functions.cc
index 28687ca..5d95e49 100644
--- a/runtime/bin/ffi_test_functions.cc
+++ b/runtime/bin/ffi_test_functions.cc
@@ -4,17 +4,13 @@
 
 // This file contains test functions for the dart:ffi test cases.
 
+// The tests which use this don't run on Windows yet.
+#if !defined(_WIN32)
+
 #include <stddef.h>
 #include <stdlib.h>
 #include <sys/types.h>
-
-#include "platform/globals.h"
-#if defined(HOST_OS_WINDOWS)
-#include <psapi.h>
-#else
 #include <unistd.h>
-#endif
-
 #include <iostream>
 #include <limits>
 
@@ -410,7 +406,6 @@
   return reinterpret_cast<void*>(-0x80000000L);
 }
 
-#if !defined(_WIN32)
 DART_EXPORT int RedirectStderr() {
   char filename[256];
   snprintf(filename, sizeof(filename), "/tmp/captured_stderr_%d", getpid());
@@ -418,6 +413,7 @@
   printf("Got file %s\n", filename);
   return getpid();
 }
-#endif
 
 }  // namespace dart
+
+#endif
diff --git a/runtime/lib/ffi.cc b/runtime/lib/ffi.cc
index d084216..4186a1e 100644
--- a/runtime/lib/ffi.cc
+++ b/runtime/lib/ffi.cc
@@ -500,9 +500,9 @@
 #elif !defined(TARGET_ARCH_X64)
   // https://github.com/dart-lang/sdk/issues/35774
   UNREACHABLE();
-#elif !defined(TARGET_OS_LINUX) && !defined(TARGET_OS_MACOS) &&                \
-    !defined(TARGET_OS_WINDOWS)
+#elif !defined(TARGET_OS_LINUX) && !defined(TARGET_OS_MACOS)
   // https://github.com/dart-lang/sdk/issues/35760 Arm32 && Android
+  // https://github.com/dart-lang/sdk/issues/35771 Windows
   // https://github.com/dart-lang/sdk/issues/35772 Arm64
   // https://github.com/dart-lang/sdk/issues/35773 DBC
   UNREACHABLE();
@@ -588,9 +588,9 @@
 #elif !defined(TARGET_ARCH_X64)
   // https://github.com/dart-lang/sdk/issues/35774
   UNREACHABLE();
-#elif !defined(TARGET_OS_LINUX) && !defined(TARGET_OS_MACOS) &&                \
-    !defined(TARGET_OS_WINDOWS)
+#elif !defined(TARGET_OS_LINUX) && !defined(TARGET_OS_MACOS)
   // https://github.com/dart-lang/sdk/issues/35760 Arm32 && Android
+  // https://github.com/dart-lang/sdk/issues/35771 Windows
   // https://github.com/dart-lang/sdk/issues/35772 Arm64
   // https://github.com/dart-lang/sdk/issues/35773 DBC
   UNREACHABLE();
diff --git a/runtime/lib/ffi_dynamic_library.cc b/runtime/lib/ffi_dynamic_library.cc
index 6d2f2af..3af92da 100644
--- a/runtime/lib/ffi_dynamic_library.cc
+++ b/runtime/lib/ffi_dynamic_library.cc
@@ -3,12 +3,12 @@
 // BSD-style license that can be found in the LICENSE file.
 
 #if !defined(TARGET_OS_LINUX) && !defined(TARGET_OS_MACOS)
-// TODO(dacoharkes): Implement dynamic libraries for other targets & merge the
-// implementation with:
-// - runtime/bin/extensions.h
+// TODO(dacoharkes): implement dynamic libraries for other targets.
+// see
+// - runtime/vm/native_symbol.h
+// - runtime/vm/native_symbol_linux.cc
+// - runtime/bin/extensions.h (but we cannot import from bin)
 // - runtime/bin/extensions_linux.cc
-// TODO(dacoharkes): Make the code from bin available in a manner similar to
-// runtime/vm/dart.h Dart_FileReadCallback.
 #else
 #include <dlfcn.h>
 #endif
@@ -19,81 +19,29 @@
 
 namespace dart {
 
-static void* LoadExtensionLibrary(const char* library_file) {
-#if defined(TARGET_OS_LINUX) || defined(TARGET_OS_MACOS)
-  void* handle = dlopen(library_file, RTLD_LAZY);
+DEFINE_NATIVE_ENTRY(Ffi_dl_open, 0, 1) {
+#if !defined(TARGET_OS_LINUX) && !defined(TARGET_OS_MACOS)
+  UNREACHABLE();
+#else
+  GET_NON_NULL_NATIVE_ARGUMENT(String, lib_path, arguments->NativeArgAt(0));
+
+  dlerror();  // Clear any errors.
+  void* handle = dlopen(lib_path.ToCString(), RTLD_LAZY);
   if (handle == nullptr) {
     char* error = dlerror();
     const String& msg = String::Handle(
-        String::NewFormatted("Failed to load dynamic library (%s)", error));
+        String::NewFormatted("Failed to load dynamic library(%s)", error));
     Exceptions::ThrowArgumentError(msg);
   }
 
-  return handle;
-#elif defined(TARGET_OS_WINDOWS)
-  SetLastError(0);  // Clear any errors.
-
-  // Convert to wchar_t string.
-  const int name_len =
-      MultiByteToWideChar(CP_UTF8, 0, library_file, -1, NULL, 0);
-  wchar_t* name = new wchar_t[name_len];
-  MultiByteToWideChar(CP_UTF8, 0, library_file, -1, name, name_len);
-
-  void* ext = LoadLibraryW(name);
-  delete[] name;
-
-  if (ext == nullptr) {
-    const int error = GetLastError();
-    const String& msg = String::Handle(
-        String::NewFormatted("Failed to load dynamic library (%i)", error));
-    Exceptions::ThrowArgumentError(msg);
-  }
-
-  return ext;
-#else
-  const auto& message =
-      String::Handle("The dart:ffi library is not available on this platform.");
-  Exceptions::ThrowByType(Exceptions::kUnsupported, message);
-#endif
-}
-
-DEFINE_NATIVE_ENTRY(Ffi_dl_open, 0, 1) {
-  GET_NON_NULL_NATIVE_ARGUMENT(String, lib_path, arguments->NativeArgAt(0));
-
-  void* handle = LoadExtensionLibrary(lib_path.ToCString());
-
   return DynamicLibrary::New(handle);
-}
-
-static void* ResolveSymbol(void* handle, const char* symbol) {
-#if defined(TARGET_OS_LINUX) || defined(TARGET_OS_MACOS)
-  dlerror();  // Clear any errors.
-  void* pointer = dlsym(handle, symbol);
-  if (pointer == nullptr) {
-    char* error = dlerror();
-    const String& msg = String::Handle(
-        String::NewFormatted("Failed to lookup symbol (%s)", error));
-    Exceptions::ThrowArgumentError(msg);
-  }
-  return pointer;
-#elif defined(TARGET_OS_WINDOWS)
-  SetLastError(0);
-  void* pointer = GetProcAddress(reinterpret_cast<HMODULE>(handle), symbol);
-  if (pointer == nullptr) {
-    const int error = GetLastError();
-    const String& msg = String::Handle(
-        String::NewFormatted("Failed to lookup symbol (%i)", error));
-    Exceptions::ThrowArgumentError(msg);
-  }
-  return pointer;
-#else
-  const auto& message =
-      String::Handle("The dart:ffi library is not available on this platform.");
-  Exceptions::ThrowByType(Exceptions::kUnsupported, message);
 #endif
 }
 
 DEFINE_NATIVE_ENTRY(Ffi_dl_lookup, 1, 2) {
+#if !defined(TARGET_OS_LINUX) && !defined(TARGET_OS_MACOS)
+  UNREACHABLE();
+#else
   GET_NATIVE_TYPE_ARGUMENT(type_arg, arguments->NativeTypeArgAt(0));
 
   GET_NON_NULL_NATIVE_ARGUMENT(DynamicLibrary, dlib, arguments->NativeArgAt(0));
@@ -102,14 +50,22 @@
 
   void* handle = dlib.GetHandle();
 
-  const intptr_t pointer = reinterpret_cast<intptr_t>(
-      ResolveSymbol(handle, argSymbolName.ToCString()));
+  dlerror();  // Clear any errors.
+  intptr_t pointer =
+      reinterpret_cast<intptr_t>(dlsym(handle, argSymbolName.ToCString()));
+  char* error;
+  if ((error = dlerror()) != NULL) {
+    const String& msg = String::Handle(
+        String::NewFormatted("Failed to lookup symbol (%s)", error));
+    Exceptions::ThrowArgumentError(msg);
+  }
 
-  // TODO(dacoharkes): should this return Object::null() if address is 0?
+  // TODO(dacoharkes): should this return NULL if addres is 0?
   // https://github.com/dart-lang/sdk/issues/35756
   RawPointer* result =
       Pointer::New(type_arg, Integer::Handle(zone, Integer::New(pointer)));
   return result;
+#endif
 }
 
 DEFINE_NATIVE_ENTRY(Ffi_dl_getHandle, 0, 1) {
diff --git a/runtime/vm/dart_api_impl.h b/runtime/vm/dart_api_impl.h
index 0bdeec5..f826323 100644
--- a/runtime/vm/dart_api_impl.h
+++ b/runtime/vm/dart_api_impl.h
@@ -300,9 +300,9 @@
 #if !defined(TARGET_ARCH_X64)
     // https://github.com/dart-lang/sdk/issues/35774
     return false;
-#elif !defined(TARGET_OS_LINUX) && !defined(TARGET_OS_MACOS) &&                \
-    !defined(TARGET_OS_WINDOWS)
+#elif !defined(TARGET_OS_LINUX) && !defined(TARGET_OS_MACOS)
     // https://github.com/dart-lang/sdk/issues/35760 Arm32 && Android
+    // https://github.com/dart-lang/sdk/issues/35771 Windows
     // https://github.com/dart-lang/sdk/issues/35772 Arm64
     // https://github.com/dart-lang/sdk/issues/35773 DBC
     return false;
diff --git a/samples/ffi/dylib_utils.dart b/samples/ffi/dylib_utils.dart
index 1c924d4..1929961 100644
--- a/samples/ffi/dylib_utils.dart
+++ b/samples/ffi/dylib_utils.dart
@@ -9,7 +9,6 @@
   if (path == null) path = "";
   if (Platform.isLinux) return path + "lib" + name + ".so";
   if (Platform.isMacOS) return path + "lib" + name + ".dylib";
-  if (Platform.isWindows) return path + name + ".dll";
   throw Exception("Platform not implemented");
 }
 
diff --git a/tests/standalone_2/ffi/dylib_utils.dart b/tests/standalone_2/ffi/dylib_utils.dart
index 1c924d4..1929961 100644
--- a/tests/standalone_2/ffi/dylib_utils.dart
+++ b/tests/standalone_2/ffi/dylib_utils.dart
@@ -9,7 +9,6 @@
   if (path == null) path = "";
   if (Platform.isLinux) return path + "lib" + name + ".so";
   if (Platform.isMacOS) return path + "lib" + name + ".dylib";
-  if (Platform.isWindows) return path + name + ".dll";
   throw Exception("Platform not implemented");
 }
 
diff --git a/tests/standalone_2/ffi/function_stress_test.dart b/tests/standalone_2/ffi/function_stress_test.dart
index 46e716f..2f5f02c 100644
--- a/tests/standalone_2/ffi/function_stress_test.dart
+++ b/tests/standalone_2/ffi/function_stress_test.dart
@@ -32,7 +32,7 @@
 }
 
 main() async {
-  final watcher = GCWatcher.ifAvailable();
+  final watcher = GCWatcher();
   try {
     await test(watcher, testBoxInt64);
     // On 64-bit platforms this won't trigger GC because the result fits into a
diff --git a/tests/standalone_2/ffi/gc_helper.dart b/tests/standalone_2/ffi/gc_helper.dart
index 5e9431d..084a0ce 100644
--- a/tests/standalone_2/ffi/gc_helper.dart
+++ b/tests/standalone_2/ffi/gc_helper.dart
@@ -3,48 +3,25 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:io';
+import 'dart:convert';
 import 'dylib_utils.dart';
 import 'dart:ffi';
-import 'dart:io' show Platform;
 
 DynamicLibrary ffiTestFunctions = dlopenPlatformSpecific("ffi_test_functions");
 
-abstract class GCWatcher {
-  factory GCWatcher() => _GCWatcherImpl();
-  factory GCWatcher.dummy() => _MockGCWatcher();
-  factory GCWatcher.ifAvailable() =>
-      Platform.isWindows ? GCWatcher.dummy() : GCWatcher();
-
-  Future<int> size();
-  void dispose();
-}
-
 // Requires --verbose-gc.
-class _GCWatcherImpl implements GCWatcher {
+class GCWatcher {
   int _suffix;
 
   Future<int> size() async {
     return await File("/tmp/captured_stderr_$_suffix").length();
   }
 
-  _GCWatcherImpl() {
+  GCWatcher() {
     print("Starting...");
     _suffix = ffiTestFunctions
         .lookupFunction<Int32 Function(), int Function()>("RedirectStderr")();
   }
 
-  dispose() {
-    try {
-      File("/tmp/captured_stderr_$_suffix").deleteSync();
-    } catch (e) {
-      print("deleting file failed");
-    }
-  }
-}
-
-class _MockGCWatcher implements GCWatcher {
-  int _ctr = 0;
-
-  Future<int> size() async => ++_ctr;
-  dispose() {}
+  dispose() => File("/tmp/captured_stderr_$_suffix").deleteSync();
 }
diff --git a/tests/standalone_2/ffi/subtype_test.dart b/tests/standalone_2/ffi/subtype_test.dart
index 22dbe13..dd466ae 100644
--- a/tests/standalone_2/ffi/subtype_test.dart
+++ b/tests/standalone_2/ffi/subtype_test.dart
@@ -39,7 +39,7 @@
   CString cs = ffi.fromAddress<CString>(11);
   bar = cs;
   foo = "";
-  final watcher = GCWatcher.ifAvailable();
+  final watcher = GCWatcher();
   int counts = await watcher.size();
   for (int i = 0; i < 1000000; ++i) {
     foo = new X(i);
diff --git a/tests/standalone_2/standalone_2_kernel.status b/tests/standalone_2/standalone_2_kernel.status
index 31ebd3d..a68bdd7 100644
--- a/tests/standalone_2/standalone_2_kernel.status
+++ b/tests/standalone_2/standalone_2_kernel.status
@@ -229,8 +229,8 @@
 io/web_socket_compression_test: Skip # Timeout
 io/web_socket_test: Skip # Timeout
 
-[ $arch != x64 || $compiler != dartk || $mode == product || $system != linux && $system != macos ]
-ffi/function_stress_test: SkipByDesign # FFI must be supported. Also requires --verbose-gc, which isn't included in product. Windows issues will be fixed in IL CL: https://github.com/dart-lang/sdk/issues/36138
+[ $arch != x64 || $compiler != dartk || $mode == product || $system != linux && $system != macos]
+ffi/function_stress_test: SkipByDesign # FFI must be supported. Also requires --verbose-gc, which isn't included in product.
 ffi/subtype_test: SkipByDesign # FFI must be supported. Also requires --verbose-gc, which isn't included in product.
 
 [ $mode == product || $mode != product ]
diff --git a/tests/standalone_2/standalone_2_vm.status b/tests/standalone_2/standalone_2_vm.status
index 1cb8be7..49b61dc 100644
--- a/tests/standalone_2/standalone_2_vm.status
+++ b/tests/standalone_2/standalone_2_vm.status
@@ -133,5 +133,5 @@
 link_natives_lazily_test: SkipByDesign # SIMDBC interpreter doesn't support lazy linking of natives.
 no_lazy_dispatchers_test: SkipByDesign # SIMDBC interpreter doesn't support --no_lazy_dispatchers
 
-[ $arch != x64 || $system != linux && $system != macos && $system != windows ]
+[ $arch != x64 || $system != linux && $system != macos ]
 ffi: Skip # ffi not yet supported on other systems than linux/macos 64