diff --git a/cc/test.go b/cc/test.go
index ead7877..5703571 100644
--- a/cc/test.go
+++ b/cc/test.go
@@ -30,7 +30,8 @@
 	// if set, build against the gtest library. Defaults to true.
 	Gtest *bool
 
-	// if set, use the isolated gtest runner. Defaults to false.
+	// if set, use the isolated gtest runner. Defaults to true if gtest is also true and the arch is Windows, false
+	// otherwise.
 	Isolated *bool
 }
 
@@ -256,6 +257,13 @@
 	return BoolDefault(test.LinkerProperties.Gtest, true)
 }
 
+func (test *testDecorator) isolated(ctx BaseModuleContext) bool {
+	if !ctx.Windows() {
+		return BoolDefault(test.LinkerProperties.Isolated, false)
+	}
+	return BoolDefault(test.LinkerProperties.Isolated, false)
+}
+
 func (test *testDecorator) testBinary() bool {
 	return true
 }
@@ -288,7 +296,7 @@
 	if test.gtest() {
 		if ctx.useSdk() && ctx.Device() {
 			deps.StaticLibs = append(deps.StaticLibs, "libgtest_main_ndk_c++", "libgtest_ndk_c++")
-		} else if BoolDefault(test.LinkerProperties.Isolated, false) {
+		} else if test.isolated(ctx) {
 			deps.StaticLibs = append(deps.StaticLibs, "libgtest_isolated_main")
 			// The isolated library requires liblog, but adding it
 			// as a static library means unit tests cannot override
@@ -424,7 +432,7 @@
 		var options []tradefed.Option
 		configs = append(configs, tradefed.Object{"target_preparer", "com.android.tradefed.targetprep.StopServicesSetup", options})
 	}
-	if Bool(test.testDecorator.LinkerProperties.Isolated) {
+	if test.isolated(ctx) {
 		configs = append(configs, tradefed.Option{Name: "not-shardable", Value: "true"})
 	}
 	if test.Properties.Test_options.Run_test_as != nil {