diff --git a/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.get/locale.money.get.members/get_long_double_fr_FR.pass.cpp b/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.get/locale.money.get.members/get_long_double_fr_FR.pass.cpp
--- a/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.get/locale.money.get.members/get_long_double_fr_FR.pass.cpp
+++ b/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.get/locale.money.get.members/get_long_double_fr_FR.pass.cpp
@@ -11,7 +11,6 @@
 // NetBSD does not support LC_MONETARY at the moment
 // XFAIL: netbsd
 
-// XFAIL: LIBCXX-WINDOWS-FIXME
 // XFAIL: LIBCXX-AIX-FIXME
 
 // REQUIRES: locale.fr_FR.UTF-8
@@ -53,11 +52,12 @@
         : Fw(refs) {}
 };
 
-// GLIBC 2.27 and newer use U2027 (narrow non-breaking space) as a thousands sep.
-// this function converts the spaces in string inputs to that character if need
-// be. FreeBSD's locale data also uses U2027 since 2018.
+// GLIBC 2.27 and newer use U+202F NARROW NO-BREAK SPACE as a thousands separator.
+// This function converts the spaces in string inputs to U+202F if need
+// be. FreeBSD's locale data also uses U+202F, since 2018.
+// Windows uses U+00A0 NO-BREAK SPACE.
 static std::wstring convert_thousands_sep(std::wstring const& in) {
-#if defined(_CS_GNU_LIBC_VERSION) || defined(__FreeBSD__)
+#if defined(_CS_GNU_LIBC_VERSION) || defined(__FreeBSD__) || defined(_WIN32)
 #if defined(_CS_GNU_LIBC_VERSION)
   if (glibc_version_less_than("2.27"))
     return in;
@@ -72,7 +72,11 @@
       continue;
     }
     assert(in[I] == L' ');
+#if defined(_WIN32)
+    out.push_back(L'\u00A0');
+#else
     out.push_back(L'\u202F');
+#endif
   }
   return out;
 #else
diff --git a/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.put/locale.money.put.members/put_long_double_fr_FR.pass.cpp b/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.put/locale.money.put.members/put_long_double_fr_FR.pass.cpp
--- a/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.put/locale.money.put.members/put_long_double_fr_FR.pass.cpp
+++ b/libcxx/test/std/localization/locale.categories/category.monetary/locale.money.put/locale.money.put.members/put_long_double_fr_FR.pass.cpp
@@ -11,7 +11,6 @@
 // NetBSD does not support LC_MONETARY at the moment
 // XFAIL: netbsd
 
-// XFAIL: LIBCXX-WINDOWS-FIXME
 // XFAIL: LIBCXX-AIX-FIXME
 
 // REQUIRES: locale.fr_FR.UTF-8
@@ -53,11 +52,12 @@
         : Fw(refs) {}
 };
 
-// GLIBC 2.27 and newer use U2027 (narrow non-breaking space) as a thousands sep.
-// this function converts the spaces in string inputs to that character if need
-// be. FreeBSD's locale data also uses U2027 since 2018.
+// GLIBC 2.27 and newer use U+202F NARROW NO-BREAK SPACE as a thousands separator.
+// This function converts the spaces in string inputs to U+202F if need
+// be. FreeBSD's locale data also uses U+202F, since 2018.
+// Windows uses U+00A0 NO-BREAK SPACE.
 static std::wstring convert_thousands_sep(std::wstring const& in) {
-#if defined(_CS_GNU_LIBC_VERSION) || defined(__FreeBSD__)
+#if defined(_CS_GNU_LIBC_VERSION) || defined(__FreeBSD__) || defined(_WIN32)
 #if defined(_CS_GNU_LIBC_VERSION)
   if (glibc_version_less_than("2.27"))
     return in;
@@ -74,7 +74,11 @@
       continue;
     }
     assert(in[I] == L' ');
+#if defined(_WIN32)
+    out.push_back(L'\u00A0');
+#else
     out.push_back(L'\u202F');
+#endif
   }
   return out;
 #else
diff --git a/libcxx/test/std/localization/locale.categories/category.monetary/locale.moneypunct.byname/thousands_sep.pass.cpp b/libcxx/test/std/localization/locale.categories/category.monetary/locale.moneypunct.byname/thousands_sep.pass.cpp
--- a/libcxx/test/std/localization/locale.categories/category.monetary/locale.moneypunct.byname/thousands_sep.pass.cpp
+++ b/libcxx/test/std/localization/locale.categories/category.monetary/locale.moneypunct.byname/thousands_sep.pass.cpp
@@ -9,8 +9,6 @@
 // NetBSD does not support LC_MONETARY at the moment
 // XFAIL: netbsd
 
-// XFAIL: LIBCXX-WINDOWS-FIXME
-
 // REQUIRES: locale.en_US.UTF-8
 // REQUIRES: locale.fr_FR.UTF-8
 // REQUIRES: locale.ru_RU.UTF-8
@@ -114,6 +112,8 @@
 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
 #if defined(_CS_GNU_LIBC_VERSION)
     const wchar_t fr_sep = glibc_version_less_than("2.27") ? L' ' : L'\u202F';
+#elif defined(_WIN32)
+    const wchar_t fr_sep = L'\u00A0';
 #else
     const wchar_t fr_sep = L' ';
 #endif
@@ -144,6 +144,8 @@
     // FIXME libc++ specifically works around \u00A0 by translating it into
     // a regular space.
     const wchar_t wsep = glibc_version_less_than("2.27") ? L'\u00A0' : L'\u202F';
+#   elif defined(_WIN32)
+    const wchar_t wsep = L'\u00A0';
 #   else
     const wchar_t wsep = L' ';
 #   endif
diff --git a/libcxx/test/std/localization/locale.categories/facet.numpunct/locale.numpunct.byname/thousands_sep.pass.cpp b/libcxx/test/std/localization/locale.categories/facet.numpunct/locale.numpunct.byname/thousands_sep.pass.cpp
--- a/libcxx/test/std/localization/locale.categories/facet.numpunct/locale.numpunct.byname/thousands_sep.pass.cpp
+++ b/libcxx/test/std/localization/locale.categories/facet.numpunct/locale.numpunct.byname/thousands_sep.pass.cpp
@@ -9,7 +9,6 @@
 // NetBSD does not support LC_NUMERIC at the moment
 // XFAIL: netbsd
 
-// XFAIL: LIBCXX-WINDOWS-FIXME
 // XFAIL: LIBCXX-AIX-FIXME
 
 // REQUIRES: locale.en_US.UTF-8
@@ -64,7 +63,7 @@
         // The below tests work around GLIBC's use of U202F as LC_NUMERIC thousands_sep.
         std::locale l(LOCALE_fr_FR_UTF_8);
         {
-#if defined(_CS_GNU_LIBC_VERSION)
+#if defined(_CS_GNU_LIBC_VERSION) || defined(_WIN32)
             const char sep = ' ';
 #else
             const char sep = ',';
@@ -77,6 +76,8 @@
         {
 #if defined(_CS_GNU_LIBC_VERSION)
             const wchar_t wsep = glibc_version_less_than("2.27") ? L' ' : L'\u202f';
+#elif defined(_WIN32)
+            const wchar_t wsep = L'\u00A0';
 #else
             const wchar_t wsep = L',';
 #endif