--- a/taskcluster/ci/test/test-platforms.yml
+++ b/taskcluster/ci/test/test-platforms.yml
@@ -112,35 +112,35 @@ windows7-32-vm/debug:
 windows7-32-vm/opt:
     build-platform: win32/opt
     test-sets:
         - windows-vm-tests
         - external-media-tests
         - external-media-tests-slow
 
 # win32 gpu
-#windows7-32/debug:
-#    build-platform: win32/debug
-#    test-sets:
-#        - windows-gpu-tests
-#windows7-32/opt:
-#    build-platform: win32/opt
-#    test-sets:
-#        - windows-gpu-tests
+windows7-32/debug:
+    build-platform: win32/debug
+    test-sets:
+        - windows-gpu-tests
+windows7-32/opt:
+    build-platform: win32/opt
+    test-sets:
+        - windows-gpu-tests
 
 # win64 vm
 windows10-64-vm/debug:
     build-platform: win64/debug
     test-sets:
-        - windows-vm-tests
+#        - windows-vm-tests
         - external-media-tests
 windows10-64-vm/opt:
     build-platform: win64/opt
     test-sets:
-        - windows-vm-tests
+#        - windows-vm-tests
         - external-media-tests
         - external-media-tests-slow
 
 # win64 gpu
 #windows10-64/debug:
 #    build-platform: win64/debug
 #    test-sets:
 #        - windows-gpu-tests

--- a/taskcluster/ci/test/test-sets.yml
+++ b/taskcluster/ci/test/test-sets.yml
@@ -122,34 +122,34 @@ jsdcov-code-coverage-tests:
     - mochitest-devtools-chrome
     - xpcshell
 
 ##
 # Test sets still being greened up in various ways
 
 windows-vm-tests:
     - cppunit
-    #- crashtest
-    #- gtest
-    #- jittest
+    - crashtest
+    - gtest
+    - jittest
     - jsreftest
-    #- marionette
-    #- mochitest
-    #- mochitest-browser-chrome
+    - marionette
+    - mochitest
+    - mochitest-browser-chrome
     - mochitest-devtools-chrome
     - mochitest-jetpack
-    #- mochitest-media
-    #- web-platform-tests
+    - mochitest-media
+    - web-platform-tests
     - web-platform-tests-reftests
     #- xpcshell
 
-# windows-gpu-tests:
-#    - reftest
-#    - reftest-no-accel
-#    - mochitest-webgl
+windows-gpu-tests:
+    - reftest
+    - reftest-no-accel
+    - mochitest-webgl
 
 # these tests currently run on hardware, but may migrate above when validated
 #    - mochitest-a11y
 #    - mochitest-chrome
 #    - mochitest-clipboard
 #    - mochitest-gpu
 
 macosx64-tests-debug:

--- a/taskcluster/ci/test/tests.yml
+++ b/taskcluster/ci/test/tests.yml
@@ -868,16 +868,17 @@ mochitest-webgl:
             default: 3
     e10s:
       by-test-platform:
         macosx.*: true
         default: both
     loopback-video: true
     max-run-time:
         by-test-platform:
+            windows.*: 5400
             android.*: 7200
             default: 3600
     instance-size:
         by-test-platform:
             android.*: xlarge
             default: default
     # Bug 1296733: llvmpipe with mesa 9.2.1 lacks thread safety
     allow-software-gl-layers: false
@@ -974,16 +975,18 @@ reftest:
             macosx64/debug: 2
             default: 8
     max-run-time:
         by-test-platform:
             android.*: 10800
             default: 3600
     e10s:
         by-test-platform:
+            # bug 1351272
+            windows7-32/debug: false
             macosx.*: true
             default: both
     mozharness:
         by-test-platform:
             android.*:
                 script: android_emulator_unittest.py
                 no-read-buildbot-config: true
                 config:
@@ -1018,16 +1021,21 @@ reftest-no-accel:
     run-on-projects:
         by-test-platform:
             linux64-qr/.*: ['graphics', 'mozilla-central']
             default: ['all']
     chunks:
         by-test-platform:
             macosx.*: 1
             default: 8
+    e10s:
+        by-test-platform:
+            # bug 1351272
+            windows7-32/debug: false
+            default: both
     mozharness:
         script: desktop_unittest.py
         no-read-buildbot-config: true
         config:
             by-test-platform:
                 windows.*:
                     - unittests/win_taskcluster_unittest.py
                 macosx.*:

--- a/taskcluster/taskgraph/transforms/tests.py
+++ b/taskcluster/taskgraph/transforms/tests.py
@@ -269,21 +269,21 @@ test_description_schema = Schema({
     # the platform on which the tests will run
     'test-platform': basestring,
 
     # the name of the test (the key in tests.yml)
     'test-name': basestring,
 
     # the product name, defaults to firefox
     Optional('product'): basestring,
-
-    # conditional files to determine when these tests should be run
-    Optional('when'): Any({
-        Optional('files-changed'): [basestring],
-    }),
+
+    # conditional files to determine when these tests should be run
+    Optional('when'): Any({
+        Optional('files-changed'): [basestring],
+    }),
 
 }, required=True)
 
 
 @transforms.add
 def validate(config, tests):
     for test in tests:
         yield validate_schema(test_description_schema, test,
@@ -415,18 +415,17 @@ def set_tier(config, tests):
                                          'linux64-nightly/opt',
                                          'linux64/debug',
                                          'linux64-pgo/opt',
                                          'linux64-asan/opt',
                                          'android-4.3-arm7-api-15/opt',
                                          'android-4.3-arm7-api-15/debug',
                                          'android-4.2-x86/opt']:
                 test['tier'] = 1
-            elif test['test-platform'].startswith('windows') \
-                    or test['worker-implementation'] == 'native-engine':
+            elif test['worker-implementation'] == 'native-engine':
                 test['tier'] = 3
             else:
                 test['tier'] = 2
         yield test
 
 
 @transforms.add
 def set_expires_after(config, tests):