Index: packages/Python/lldbsuite/test/functionalities/attach_resume/TestAttachResume.py
===================================================================
--- packages/Python/lldbsuite/test/functionalities/attach_resume/TestAttachResume.py
+++ packages/Python/lldbsuite/test/functionalities/attach_resume/TestAttachResume.py
@@ -21,7 +21,7 @@
 
     @skipIfRemote
     @expectedFailureAll(oslist=['freebsd'], bugnumber='llvm.org/pr19310')
-    @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr24778")
+    @skipIfWindows # llvm.org/pr24778, llvm.org/pr21753
     def test_attach_continue_interrupt_detach(self):
         """Test attach/continue/interrupt/detach"""
         self.build()
Index: packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_ignore_count/TestBreakpointIgnoreCount.py
===================================================================
--- packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_ignore_count/TestBreakpointIgnoreCount.py
+++ packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_ignore_count/TestBreakpointIgnoreCount.py
@@ -18,12 +18,14 @@
 
     mydir = TestBase.compute_mydir(__file__)
 
+    @skipIfWindows # This test will hang on windows llvm.org/pr21753
     def test_with_run_command(self):
         """Exercise breakpoint ignore count with 'breakpoint set -i <count>'."""
         self.build()
         self.breakpoint_ignore_count()
 
     @add_test_categories(['pyapi'])
+    @skipIfWindows # This test will hang on windows llvm.org/pr21753
     def test_with_python_api(self):
         """Use Python APIs to set breakpoint ignore count."""
         self.build()
Index: packages/Python/lldbsuite/test/functionalities/memory/cache/TestMemoryCache.py
===================================================================
--- packages/Python/lldbsuite/test/functionalities/memory/cache/TestMemoryCache.py
+++ packages/Python/lldbsuite/test/functionalities/memory/cache/TestMemoryCache.py
@@ -24,7 +24,9 @@
         # Find the line number to break inside main().
         self.line = line_number('main.cpp', '// Set break point at this line.')
 
-    @expectedFlakeyOS(oslist=["windows"])
+    # The test is actually flakey on Windows, failing every dozen or so runs, but even with the flakey
+    # decorator it still fails
+    @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr38373")
     def test_memory_cache(self):
         """Test the MemoryCache class with a sequence of 'memory read' and 'memory write' operations."""
         self.build()
Index: packages/Python/lldbsuite/test/functionalities/thread/exit_during_step/TestExitDuringStep.py
===================================================================
--- packages/Python/lldbsuite/test/functionalities/thread/exit_during_step/TestExitDuringStep.py
+++ packages/Python/lldbsuite/test/functionalities/thread/exit_during_step/TestExitDuringStep.py
@@ -18,6 +18,9 @@
     mydir = TestBase.compute_mydir(__file__)
 
     @skipIfFreeBSD  # llvm.org/pr21411: test is hanging
+    # The test is actually flakey on Windows, failing every dozen or so runs, but even with the flakey
+    # decorator it still fails
+    @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr38373")
     def test(self):
         """Test thread exit during step handling."""
         self.build(dictionary=self.getBuildFlags())
@@ -27,6 +30,9 @@
             True)
 
     @skipIfFreeBSD  # llvm.org/pr21411: test is hanging
+    # The test is actually flakey on Windows, failing every dozen or so runs, but even with the flakey
+    # decorator it still fails
+    @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr38373")
     def test_step_over(self):
         """Test thread exit during step-over handling."""
         self.build(dictionary=self.getBuildFlags())
@@ -36,6 +42,9 @@
             False)
 
     @skipIfFreeBSD  # llvm.org/pr21411: test is hanging
+    # The test is actually flakey on Windows, failing every dozen or so runs, but even with the flakey
+    # decorator it still fails
+    @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr38373")
     def test_step_in(self):
         """Test thread exit during step-in handling."""
         self.build(dictionary=self.getBuildFlags())
Index: packages/Python/lldbsuite/test/functionalities/thread/step_out/TestThreadStepOut.py
===================================================================
--- packages/Python/lldbsuite/test/functionalities/thread/step_out/TestThreadStepOut.py
+++ packages/Python/lldbsuite/test/functionalities/thread/step_out/TestThreadStepOut.py
@@ -25,6 +25,7 @@
     @expectedFailureAll(
         oslist=["freebsd"],
         bugnumber="llvm.org/pr18066 inferior does not exit")
+    @skipIfWindows # This test will hang on windows llvm.org/pr21753
     @expectedFailureAll(oslist=["windows"])
     def test_step_single_thread(self):
         """Test thread step out on one thread via command interpreter. """
@@ -39,6 +40,7 @@
     @expectedFailureAll(
         oslist=["freebsd"],
         bugnumber="llvm.org/pr19347 2nd thread stops at breakpoint")
+    @skipIfWindows # This test will hang on windows llvm.org/pr21753
     @expectedFailureAll(oslist=["windows"])
     @expectedFailureAll(oslist=["watchos"], archs=['armv7k'], bugnumber="rdar://problem/34674488") # stop reason is trace when it should be step-out
     def test_step_all_threads(self):
@@ -54,6 +56,7 @@
     @expectedFailureAll(
         oslist=["freebsd"],
         bugnumber="llvm.org/pr19347 2nd thread stops at breakpoint")
+    @skipIfWindows # This test will hang on windows llvm.org/pr21753
     @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr24681")
     def test_python(self):
         """Test thread step out on one thread via Python API (dwarf)."""
Index: packages/Python/lldbsuite/test/functionalities/thread/thread_exit/TestThreadExit.py
===================================================================
--- packages/Python/lldbsuite/test/functionalities/thread/thread_exit/TestThreadExit.py
+++ packages/Python/lldbsuite/test/functionalities/thread/thread_exit/TestThreadExit.py
@@ -8,6 +8,7 @@
 import os
 import time
 import lldb
+from lldbsuite.test.decorators import *
 from lldbsuite.test.lldbtest import *
 import lldbsuite.test.lldbutil as lldbutil
 
@@ -25,6 +26,9 @@
         self.break_3 = line_number('main.cpp', '// Set third breakpoint here')
         self.break_4 = line_number('main.cpp', '// Set fourth breakpoint here')
 
+    # The test is actually flakey on Windows, failing every dozen or so runs, but even with the flakey
+    # decorator it still fails
+    @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr38373")
     def test(self):
         """Test thread exit handling."""
         self.build(dictionary=self.getBuildFlags())
Index: packages/Python/lldbsuite/test/lang/cpp/virtual/TestVirtual.py
===================================================================
--- packages/Python/lldbsuite/test/lang/cpp/virtual/TestVirtual.py
+++ packages/Python/lldbsuite/test/lang/cpp/virtual/TestVirtual.py
@@ -36,6 +36,7 @@
     @expectedFailureAll(
         compiler="icc",
         bugnumber="llvm.org/pr16808 lldb does not call the correct virtual function with icc.")
+    @skipIfWindows # This test will hang on windows llvm.org/pr21753
     def test_virtual_madness(self):
         """Test that expression works correctly with virtual inheritance as well as virtual function."""
         self.build()
Index: packages/Python/lldbsuite/test/python_api/event/TestEvents.py
===================================================================
--- packages/Python/lldbsuite/test/python_api/event/TestEvents.py
+++ packages/Python/lldbsuite/test/python_api/event/TestEvents.py
@@ -31,6 +31,7 @@
     @expectedFailureAll(
         oslist=["linux"],
         bugnumber="llvm.org/pr23730 Flaky, fails ~1/10 cases")
+    @skipIfWindows # This test will hang on windows llvm.org/pr21753
     def test_listen_for_and_print_event(self):
         """Exercise SBEvent API."""
         self.build()