diff --git a/ci/windows/test_py2_cpu.ps1 b/ci/windows/test_py2_cpu.ps1
index 1c4a72682ae5..36c6f953fe14 100644
--- a/ci/windows/test_py2_cpu.ps1
+++ b/ci/windows/test_py2_cpu.ps1
@@ -23,7 +23,12 @@ $env:MXNET_STORAGE_FALLBACK_LOG_VERBOSE=0
 $env:MXNET_HOME=[io.path]::combine($PSScriptRoot, 'mxnet_home')
 
 C:\Python27\Scripts\pip install -r tests\requirements.txt
-C:\Python27\python.exe -m nose -v --with-timer --timer-ok 1 --timer-warning 15 --timer-filter warning,error --with-xunit --xunit-file nosetests_unittest.xml tests\python\unittest
+# C:\Python27\python.exe -m nose -v --with-timer --timer-ok 1 --timer-warning 15 --timer-filter warning,error --with-xunit --xunit-file nosetests_unittest.xml tests\python\unittest
+# if (! $?) { Throw ("Error running unittest") }
+C:\Python27\python.exe -m nose -v --with-timer --timer-ok 1 --timer-warning 15 --timer-filter warning,error --with-xunit --xunit-file nosetests_unittest.xml tests\python\unittest\test_operator.py:test_norm
 if (! $?) { Throw ("Error running unittest") }
-C:\Python27\python.exe -m nose -v --with-timer --timer-ok 1 --timer-warning 15 --timer-filter warning,error --with-xunit --xunit-file nosetests_train.xml tests\python\train
-if (! $?) { Throw ("Error running train tests") }
+$env:MXNET_SAFE_ACCUMULATION=1
+C:\Python27\python.exe -m nose -v --with-timer --timer-ok 1 --timer-warning 15 --timer-filter warning,error --with-xunit --xunit-file nosetests_unittest.xml tests\python\unittest\test_operator.py:test_norm
+if (! $?) { Throw ("Error running unittest") }
+# C:\Python27\python.exe -m nose -v --with-timer --timer-ok 1 --timer-warning 15 --timer-filter warning,error --with-xunit --xunit-file nosetests_train.xml tests\python\train
+# if (! $?) { Throw ("Error running train tests") }
diff --git a/ci/windows/test_py3_cpu.ps1 b/ci/windows/test_py3_cpu.ps1
index a7067f9f3f83..cf8d02fd00bb 100644
--- a/ci/windows/test_py3_cpu.ps1
+++ b/ci/windows/test_py3_cpu.ps1
@@ -23,7 +23,12 @@ $env:MXNET_STORAGE_FALLBACK_LOG_VERBOSE=0
 $env:MXNET_HOME=[io.path]::combine($PSScriptRoot, 'mxnet_home')
 
 C:\Python37\Scripts\pip install -r tests\requirements.txt
-C:\Python37\python.exe -m nose -v --with-timer --timer-ok 1 --timer-warning 15 --timer-filter warning,error --with-xunit --xunit-file nosetests_unittest.xml tests\python\unittest
+C:\Python37\python.exe -m nose -v --with-timer --timer-ok 1 --timer-warning 15 --timer-filter warning,error --with-xunit --xunit-file nosetests_unittest.xml tests\python\unittest\test_operator.py:test_norm
 if (! $?) { Throw ("Error running unittest") }
-C:\Python37\python.exe -m nose -v --with-timer --timer-ok 1 --timer-warning 15 --timer-filter warning,error --with-xunit --xunit-file nosetests_train.xml tests\python\train
-if (! $?) { Throw ("Error running train tests") }
+$env:MXNET_SAFE_ACCUMULATION=1
+C:\Python37\python.exe -m nose -v --with-timer --timer-ok 1 --timer-warning 15 --timer-filter warning,error --with-xunit --xunit-file nosetests_unittest.xml tests\python\unittest\test_operator.py:test_norm
+if (! $?) { Throw ("Error running unittest") }
+# C:\Python37\python.exe -m nose -v --with-timer --timer-ok 1 --timer-warning 15 --timer-filter warning,error --with-xunit --xunit-file nosetests_unittest.xml tests\python\unittest
+# if (! $?) { Throw ("Error running unittest") }
+# C:\Python37\python.exe -m nose -v --with-timer --timer-ok 1 --timer-warning 15 --timer-filter warning,error --with-xunit --xunit-file nosetests_train.xml tests\python\train
+# if (! $?) { Throw ("Error running train tests") }
diff --git a/tests/python/unittest/test_operator.py b/tests/python/unittest/test_operator.py
index 2ee471cfabc8..bc9605b29116 100644
--- a/tests/python/unittest/test_operator.py
+++ b/tests/python/unittest/test_operator.py
@@ -8401,9 +8401,13 @@ def l2norm(input_data, axis=0, keepdims=True):
                     np.int32: 'int32', np.int64: 'int64'}
     is_windows = sys.platform.startswith('win')
     for enforce_safe_acc in ["1", "0"]:
-        # os.environ["MXNET_SAFE_ACCUMULATION"] = enforce_safe_acc
-        os.putenv("MXNET_SAFE_ACCUMULATION", enforce_safe_acc)
-        # raise ValueError("in python safe_acc is: {}".format(os.environ["MXNET_SAFE_ACCUMULATION"]))
+        if is_windows:
+            if enforce_safe_acc == "0":
+                break
+            enforce_safe_acc = "0" if "MXNET_SAFE_ACCUMULATION" not in os.environ else os.environ["MXNET_SAFE_ACCUMULATION"]
+        else:
+            os.environ["MXNET_SAFE_ACCUMULATION"] = enforce_safe_acc
+        print("in python safe_acc is: {}".format(os.environ["MXNET_SAFE_ACCUMULATION"]))
         for order in [1, 2]:
             for dtype in [np.float16, np.float32, np.float64]:
                 for i in range(in_data_dim):