diff --git a/libcxx/include/__support/win32/locale_win32.h b/libcxx/include/__support/win32/locale_win32.h
--- a/libcxx/include/__support/win32/locale_win32.h
+++ b/libcxx/include/__support/win32/locale_win32.h
@@ -12,9 +12,28 @@
 
 #include <__config>
 #include <stdio.h>
-#include <xlocinfo.h> // _locale_t
+#include <locale.h> // _locale_t
 #include <__nullptr>
 
+#define _X_ALL LC_ALL
+#define _X_COLLATE LC_COLLATE
+#define _X_CTYPE LC_CTYPE
+#define _X_MONETARY LC_MONETARY
+#define _X_NUMERIC LC_NUMERIC
+#define _X_TIME LC_TIME
+#define _X_MAX LC_MAX
+#define _X_MESSAGES 6
+#define _NCAT 7
+
+#define _CATMASK(n) ((1 << (n)) >> 1)
+#define _M_COLLATE _CATMASK(_X_COLLATE)
+#define _M_CTYPE _CATMASK(_X_CTYPE)
+#define _M_MONETARY _CATMASK(_X_MONETARY)
+#define _M_NUMERIC _CATMASK(_X_NUMERIC)
+#define _M_TIME _CATMASK(_X_TIME)
+#define _M_MESSAGES _CATMASK(_X_MESSAGES)
+#define _M_ALL (_CATMASK(_NCAT) - 1)
+
 #define LC_COLLATE_MASK _M_COLLATE
 #define LC_CTYPE_MASK _M_CTYPE
 #define LC_MONETARY_MASK _M_MONETARY
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/complex.version.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/complex.version.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/complex.version.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/complex.version.pass.cpp
@@ -13,8 +13,6 @@
 
 // <complex>
 
-// XFAIL: LIBCXX-WINDOWS-FIXME
-
 // Test the feature test macros defined by <complex>
 
 /*  Constant                       Value
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/filesystem.version.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/filesystem.version.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/filesystem.version.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/filesystem.version.pass.cpp
@@ -12,7 +12,6 @@
 // clang-format off
 
 // UNSUPPORTED: libcpp-has-no-filesystem-library
-// XFAIL: LIBCXX-WINDOWS-FIXME
 
 // <filesystem>
 
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/istream.version.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/istream.version.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/istream.version.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/istream.version.pass.cpp
@@ -12,7 +12,6 @@
 // clang-format off
 
 // UNSUPPORTED: libcpp-has-no-localization
-// XFAIL: LIBCXX-WINDOWS-FIXME
 
 // <istream>
 
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/locale.version.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/locale.version.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/locale.version.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/locale.version.pass.cpp
@@ -12,7 +12,6 @@
 // clang-format off
 
 // UNSUPPORTED: libcpp-has-no-localization
-// XFAIL: LIBCXX-WINDOWS-FIXME
 
 // <locale>
 
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/ostream.version.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/ostream.version.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/ostream.version.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/ostream.version.pass.cpp
@@ -12,7 +12,6 @@
 // clang-format off
 
 // UNSUPPORTED: libcpp-has-no-localization
-// XFAIL: LIBCXX-WINDOWS-FIXME
 
 // <ostream>