Index: utils/lit/tests/discovery.py
===================================================================
--- utils/lit/tests/discovery.py
+++ utils/lit/tests/discovery.py
@@ -1,5 +1,8 @@
 # Check the basic discovery process, including a sub-suite.
 #
+# PR33932
+# XFAIL: windows
+#
 # RUN: %{lit} %{inputs}/discovery \
 # RUN:   -j 1 --debug --show-tests --show-suites \
 # RUN:   -v > %t.out 2> %t.err
Index: utils/lit/tests/googletest-format.py
===================================================================
--- utils/lit/tests/googletest-format.py
+++ utils/lit/tests/googletest-format.py
@@ -1,5 +1,8 @@
 # Check the various features of the GoogleTest format.
 #
+# PR33933
+# XFAIL: windows
+#
 # RUN: not %{lit} -j 1 -v %{inputs}/googletest-format > %t.out
 # RUN: FileCheck < %t.out %s
 #
Index: utils/lit/tests/googletest-timeout.py
===================================================================
--- utils/lit/tests/googletest-timeout.py
+++ utils/lit/tests/googletest-timeout.py
@@ -1,5 +1,8 @@
 # REQUIRES: python-psutil
 
+# PR33934
+# XFAIL: windows
+
 # Check that the per test timeout is enforced when running GTest tests.
 #
 # RUN: not %{lit} -j 1 -v %{inputs}/googletest-timeout --timeout=1 > %t.cmd.out
Index: utils/lit/tests/googletest-upstream-format.py
===================================================================
--- utils/lit/tests/googletest-upstream-format.py
+++ utils/lit/tests/googletest-upstream-format.py
@@ -1,5 +1,8 @@
 # Check the various features of the GoogleTest format.
 #
+# PR33935
+# XFAIL: windows
+#
 # RUN: not %{lit} -j 1 -v %{inputs}/googletest-upstream-format > %t.out
 # RUN: FileCheck < %t.out %s
 #
Index: utils/lit/tests/lit.cfg
===================================================================
--- utils/lit/tests/lit.cfg
+++ utils/lit/tests/lit.cfg
@@ -52,3 +52,6 @@
 except ImportError:
     lit_config.warning('Could not import psutil. Some tests will be skipped and'
                        ' the --timeout command line argument will not work.')
+
+if sys.platform.startswith('win') or sys.platform.startswith('cygwin'):
+    config.available_features.add('windows')
Index: utils/lit/tests/max-failures.py
===================================================================
--- utils/lit/tests/max-failures.py
+++ utils/lit/tests/max-failures.py
@@ -1,5 +1,8 @@
 # Check the behavior of --max-failures option.
 #
+# PR33941
+# XFAIL: windows
+#
 # RUN: not %{lit} -j 1 -v %{inputs}/shtest-shell > %t.out
 # RUN: not %{lit} --max-failures=1 -j 1 -v %{inputs}/shtest-shell >> %t.out
 # RUN: not %{lit} --max-failures=2 -j 1 -v %{inputs}/shtest-shell >> %t.out
Index: utils/lit/tests/selecting.py
===================================================================
--- utils/lit/tests/selecting.py
+++ utils/lit/tests/selecting.py
@@ -1,6 +1,8 @@
 # RUN: %{lit} %{inputs}/discovery | FileCheck --check-prefix=CHECK-BASIC %s
 # CHECK-BASIC: Testing: 5 tests
 
+# PR33937
+# XFAIL: windows
 
 # Check that regex-filtering works
 #
Index: utils/lit/tests/shtest-format.py
===================================================================
--- utils/lit/tests/shtest-format.py
+++ utils/lit/tests/shtest-format.py
@@ -1,5 +1,8 @@
 # Check the various features of the ShTest format.
 #
+# PR33939
+# XFAIL: windows
+#
 # RUN: not %{lit} -j 1 -v %{inputs}/shtest-format > %t.out
 # RUN: FileCheck < %t.out %s
 #
Index: utils/lit/tests/shtest-output-printing.py
===================================================================
--- utils/lit/tests/shtest-output-printing.py
+++ utils/lit/tests/shtest-output-printing.py
@@ -1,5 +1,8 @@
 # Check the various features of the ShTest format.
 #
+# PR33938
+# XFAIL: windows
+#
 # RUN: not %{lit} -j 1 -v %{inputs}/shtest-output-printing > %t.out
 # RUN: FileCheck --input-file %t.out %s
 #
Index: utils/lit/tests/shtest-shell.py
===================================================================
--- utils/lit/tests/shtest-shell.py
+++ utils/lit/tests/shtest-shell.py
@@ -1,5 +1,8 @@
 # Check the internal shell handling component of the ShTest format.
 #
+# PR33940
+# XFAIL: windows
+#
 # RUN: not %{lit} -j 1 -v %{inputs}/shtest-shell > %t.out
 # RUN: FileCheck --input-file %t.out %s
 #
Index: utils/lit/tests/shtest-timeout.py
===================================================================
--- utils/lit/tests/shtest-timeout.py
+++ utils/lit/tests/shtest-timeout.py
@@ -1,5 +1,8 @@
 # REQUIRES: python-psutil
 
+# PR33944
+# XFAIL: windows
+
 # Test per test timeout using external shell
 # RUN: not %{lit} \
 # RUN: %{inputs}/shtest-timeout/infinite_loop.py \
Index: utils/lit/tests/unit/TestRunner.py
===================================================================
--- utils/lit/tests/unit/TestRunner.py
+++ utils/lit/tests/unit/TestRunner.py
@@ -1,5 +1,8 @@
 # RUN: %{python} %s
 #
+# PR33942
+# XFAIL: windows
+#
 # END.
 
 
Index: utils/lit/tests/unittest-adaptor.py
===================================================================
--- utils/lit/tests/unittest-adaptor.py
+++ utils/lit/tests/unittest-adaptor.py
@@ -1,5 +1,8 @@
 # Check the lit adaption to run under unittest.
 #
+# PR33943
+# XFAIL: windows
+#
 # RUN: %{python} %s %{inputs}/unittest-adaptor 2> %t.err
 # RUN: FileCheck < %t.err %s
 #