--- a/mozilla-tests/config.py
+++ b/mozilla-tests/config.py
@@ -3293,26 +3293,31 @@ for branch_name in ('try',):
         if platform in ('linux64-asan', 'linux64-cc', 'linux64-tsan'):
             continue
 
         platform_info = PLATFORMS.get(platform)
         for slave_platform in platform_info.get('slave_platforms'):
             if slave_platform in branch['platforms'][platform]:
                 branch['platforms'][platform][slave_platform]['opt_unittest_suites'] += \
                     MOCHITEST_GPU + MOCHITEST_CLIPBOARD
-                branch['platforms'][platform][slave_platform]['opt_unittest_suites'] += \
-                    MOCHITEST_GPU_E10S + MOCHITEST_CLIPBOARD_E10S
+
+                # we don't run e10s on winxp
+                if slave_platform != 'xp_ix':
+                    branch['platforms'][platform][slave_platform]['opt_unittest_suites'] += \
+                        MOCHITEST_GPU_E10S + MOCHITEST_CLIPBOARD_E10S
 
                 # Do not add Linux x64 debug since it is running on TaskCluster
-                if slave_platform == 'ubuntu64_vm':
-                    continue
-                branch['platforms'][platform][slave_platform]['debug_unittest_suites'] += \
-                    MOCHITEST_GPU + MOCHITEST_CLIPBOARD
-                branch['platforms'][platform][slave_platform]['debug_unittest_suites'] += \
-                    MOCHITEST_GPU_E10S + MOCHITEST_CLIPBOARD_E10S
+                if slave_platform != 'ubuntu64_vm':
+                    branch['platforms'][platform][slave_platform]['debug_unittest_suites'] += \
+                        MOCHITEST_GPU + MOCHITEST_CLIPBOARD
+
+                # currently we don't run e10s tests on winxp debug or win8 debug
+                if slave_platform not in ('xp_ix', 'win8_64', 'ubuntu64_vm'):
+                    branch['platforms'][platform][slave_platform]['debug_unittest_suites'] += \
+                        MOCHITEST_GPU_E10S + MOCHITEST_CLIPBOARD_E10S
 
 
 ### Test suites that only run on Try ###
 
 # Enable linux64-cc, linux64-tsan, and win10 on Try only
 delete_slave_platform(BRANCHES, PLATFORMS, {'win64': 'win10_64'}, branch_exclusions=["try"])