diff --git a/lldb/packages/Python/lldbsuite/test/dotest.py b/lldb/packages/Python/lldbsuite/test/dotest.py
--- a/lldb/packages/Python/lldbsuite/test/dotest.py
+++ b/lldb/packages/Python/lldbsuite/test/dotest.py
@@ -52,6 +52,9 @@
     """Returns true if fpath is an executable."""
     if fpath == None:
         return False
+    if sys.platform == 'win32':
+        if not fpath.endswith(".exe"):
+            fpath += ".exe"
     return os.path.isfile(fpath) and os.access(fpath, os.X_OK)
 
 
diff --git a/lldb/packages/Python/lldbsuite/test_event/build_exception.py b/lldb/packages/Python/lldbsuite/test_event/build_exception.py
--- a/lldb/packages/Python/lldbsuite/test_event/build_exception.py
+++ b/lldb/packages/Python/lldbsuite/test_event/build_exception.py
@@ -12,4 +12,4 @@
     @staticmethod
     def format_build_error(command, command_output):
         return "Error when building test subject.\n\nBuild Command:\n{}\n\nBuild Command Output:\n{}".format(
-            command, command_output.decode("utf-8"))
+            command, command_output.decode("utf-8", errors='ignore'))
diff --git a/lldb/test/API/commands/target/basic/TestTargetCommand.py b/lldb/test/API/commands/target/basic/TestTargetCommand.py
--- a/lldb/test/API/commands/target/basic/TestTargetCommand.py
+++ b/lldb/test/API/commands/target/basic/TestTargetCommand.py
@@ -353,7 +353,7 @@
     @no_debug_info_test
     def test_target_create_nonexistent_core_file(self):
         self.expect("target create -c doesntexist", error=True,
-                    patterns=["Cannot open 'doesntexist'", ": (No such file or directory|The system cannot find the file specified)"])
+                    patterns=["Cannot open 'doesntexist'", ": (No such file or directory|The system cannot find the file specified|Le fichier sp\udce9cifi\udce9 est introuvable)"])
 
     # Write only files don't seem to be supported on Windows.
     @skipIfWindows
@@ -368,7 +368,7 @@
     @no_debug_info_test
     def test_target_create_nonexistent_sym_file(self):
         self.expect("target create -s doesntexist doesntexisteither", error=True,
-                    patterns=["Cannot open '", ": (No such file or directory|The system cannot find the file specified)"])
+                    patterns=["Cannot open '", ": (No such file or directory|The system cannot find the file specified|Le fichier sp\udce9cifi\udce9 est introuvable)"])
 
     @skipIfWindows
     @no_debug_info_test
diff --git a/lldb/unittests/Utility/StatusTest.cpp b/lldb/unittests/Utility/StatusTest.cpp
--- a/lldb/unittests/Utility/StatusTest.cpp
+++ b/lldb/unittests/Utility/StatusTest.cpp
@@ -10,7 +10,7 @@
 #include "gtest/gtest.h"
 
 #ifdef _WIN32
-#include <winerror.h>
+#include <windows.h>
 #endif
 
 using namespace lldb_private;
@@ -71,6 +71,14 @@
   EXPECT_FALSE(success.ToError());
   EXPECT_TRUE(success.Success());
 
+  WCHAR name[128]{};
+  GetLocaleInfoEx(LOCALE_NAME_USER_DEFAULT, LOCALE_SNAME, (LPWSTR)&name,
+                  sizeof(name) / sizeof(WCHAR));
+  // Skip the following tests on non-English, non-US, locales because the
+  // formatted messages will be different.
+  if (wcscmp(L"en-US", name) != 0)
+    return;
+
   auto s = Status(ERROR_ACCESS_DENIED, ErrorType::eErrorTypeWin32);
   EXPECT_TRUE(s.Fail());
   EXPECT_STREQ("Access is denied. ", s.AsCString());