Index: lib/fuzzer/CMakeLists.txt
===================================================================
--- lib/fuzzer/CMakeLists.txt
+++ lib/fuzzer/CMakeLists.txt
@@ -3,7 +3,7 @@
   FuzzerDataFlowTrace.cpp
   FuzzerDriver.cpp
   FuzzerExtFunctionsDlsym.cpp
-  FuzzerExtFunctionsDlsymWin.cpp
+  FuzzerExtFunctionsWeakAlias.cpp
   FuzzerExtFunctionsWeak.cpp
   FuzzerExtraCounters.cpp
   FuzzerIO.cpp
Index: lib/fuzzer/FuzzerExtFunctionsDlsymWin.cpp
===================================================================
--- lib/fuzzer/FuzzerExtFunctionsDlsymWin.cpp
+++ lib/fuzzer/FuzzerExtFunctionsDlsymWin.cpp
@@ -1,62 +0,0 @@
-//===- FuzzerExtFunctionsDlsymWin.cpp - Interface to external functions ---===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-// Implementation using dynamic loading for Windows.
-//===----------------------------------------------------------------------===//
-#include "FuzzerDefs.h"
-#if LIBFUZZER_WINDOWS
-
-#include "FuzzerExtFunctions.h"
-#include "FuzzerIO.h"
-#include <windows.h>
-
-// This must be included after Windows.h.
-#include <psapi.h>
-
-namespace fuzzer {
-
-ExternalFunctions::ExternalFunctions() {
-  HMODULE Modules[1024];
-  DWORD BytesNeeded;
-  HANDLE CurrentProcess = GetCurrentProcess();
-
-  if (!EnumProcessModules(CurrentProcess, Modules, sizeof(Modules),
-                          &BytesNeeded)) {
-    Printf("EnumProcessModules failed (error: %d).\n", GetLastError());
-    exit(1);
-  }
-
-  if (sizeof(Modules) < BytesNeeded) {
-    Printf("Error: the array is not big enough to hold all loaded modules.\n");
-    exit(1);
-  }
-
-  for (size_t i = 0; i < (BytesNeeded / sizeof(HMODULE)); i++)
-  {
-    FARPROC Fn;
-#define EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN)                            \
-    if (this->NAME == nullptr) {                                               \
-      Fn = GetProcAddress(Modules[i], #NAME);                                  \
-      if (Fn == nullptr)                                                       \
-         Fn = GetProcAddress(Modules[i], #NAME "__dll");                       \
-      this->NAME = (decltype(ExternalFunctions::NAME)) Fn;                     \
-    }
-#include "FuzzerExtFunctions.def"
-#undef EXT_FUNC
-  }
-
-#define EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN)                            \
-  if (this->NAME == nullptr && WARN)                                           \
-    Printf("WARNING: Failed to find function \"%s\".\n", #NAME);
-#include "FuzzerExtFunctions.def"
-#undef EXT_FUNC
-}
-
-} // namespace fuzzer
-
-#endif // LIBFUZZER_WINDOWS
Index: test/fuzzer/bogus-initialize.test
===================================================================
--- test/fuzzer/bogus-initialize.test
+++ test/fuzzer/bogus-initialize.test
@@ -1,5 +1,3 @@
-# FIXME: Disabled on Windows since LLVMFuzzerInitialize does not yet work.
-UNSUPPORTED: windows
 RUN: %cpp_compiler %S/BogusInitializeTest.cpp -o %t-BogusInitializeTest
 
 RUN: not %run %t-BogusInitializeTest 2>&1 | FileCheck %s --check-prefix=BOGUS_INITIALIZE
Index: test/fuzzer/fuzzer-customcrossover.test
===================================================================
--- test/fuzzer/fuzzer-customcrossover.test
+++ test/fuzzer/fuzzer-customcrossover.test
@@ -1,5 +1,3 @@
-# FIXME: Disabled on Windows since LLVMFuzzerCustomCrossOver does not yet work.
-UNSUPPORTED: windows
 RUN: %cpp_compiler %S/CustomCrossOverTest.cpp -o %t-CustomCrossOverTest
 
 RUN: not %run %t-CustomCrossOverTest -seed=1 -runs=1000000                2>&1 | FileCheck %s --check-prefix=CHECK_CO
Index: test/fuzzer/fuzzer-custommutator.test
===================================================================
--- test/fuzzer/fuzzer-custommutator.test
+++ test/fuzzer/fuzzer-custommutator.test
@@ -1,5 +1,3 @@
-# FIXME: Disabled on Windows since LLVMFuzzerCustomMutator does not yet work.
-UNSUPPORTED: windows
 RUN: %cpp_compiler %S/CustomMutatorTest.cpp -o %t-CustomMutatorTest
 RUN: not %run %t-CustomMutatorTest 2>&1 | FileCheck %s --check-prefix=LLVMFuzzerCustomMutator
 LLVMFuzzerCustomMutator: In LLVMFuzzerCustomMutator
Index: test/fuzzer/fuzzer-flags.test
===================================================================
--- test/fuzzer/fuzzer-flags.test
+++ test/fuzzer/fuzzer-flags.test
@@ -1,6 +1,3 @@
-# FIXME: Disabled on Windows since LLVMFuzzerInitialize does not yet work.
-UNSUPPORTED: windows
-RUN: %cpp_compiler %S/FlagsTest.cpp -o %t-FlagsTest
 RUN: %run %t-FlagsTest -runs=10 -foo_bar=1 2>&1 | FileCheck %s --check-prefix=FOO_BAR
 FOO_BAR: WARNING: unrecognized flag '-foo_bar=1'; use -help=1 to list all flags
 FOO_BAR: BINGO
Index: test/fuzzer/initialize.test
===================================================================
--- test/fuzzer/initialize.test
+++ test/fuzzer/initialize.test
@@ -1,5 +1,3 @@
-# FIXME: Disabled on Windows since LLVMFuzzerInitialize does not yet work.
-UNSUPPORTED: windows
 CHECK: BINGO
 RUN: %cpp_compiler %S/InitializeTest.cpp -o %t-InitializeTest
 RUN: not %run %t-InitializeTest -use_value_profile=1 2>&1 | FileCheck %s
Index: test/fuzzer/standalone.test
===================================================================
--- test/fuzzer/standalone.test
+++ test/fuzzer/standalone.test
@@ -1,5 +1,3 @@
-# FIXME: Disabled on Windows because memmem is a GNU extension.
-UNSUPPORTED: windows
 RUN: %no_fuzzer_c_compiler %libfuzzer_src/standalone/StandaloneFuzzTargetMain.c -c -o %t_1.o
 RUN: %no_fuzzer_cpp_compiler %S/InitializeTest.cpp -c -o %t_2.o