diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index e474760893..53878351b4 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -10,11 +10,8 @@ jobs:
     test:
         strategy:
             matrix:
+                os: [ "ubuntu-latest", "windows-latest" ]
                 php: [ "8.1", "8.2", "8.3", "8.4" ]
-                os: [ ubuntu-latest ]
-                include:
-                  - os: windows-latest
-                    php: "8.1"
         runs-on: ${{ matrix.os }}
         name: PHP ${{ matrix.php }} Unit Test${{ matrix.os == 'windows-latest' && ' on Windows' || '' }}
         steps:
@@ -31,7 +28,7 @@ jobs:
                 max_attempts: 3
                 command: composer install
             - name: Run Script
-              run: vendor/bin/phpunit ${{ matrix.os == 'windows-latest' && '--filter GCECredentialsTest' || '' }}
+              run: vendor/bin/phpunit
     test_lowest:
         runs-on: ubuntu-latest
         name: Test Prefer Lowest
diff --git a/tests/ApplicationDefaultCredentialsTest.php b/tests/ApplicationDefaultCredentialsTest.php
index 1db9b9e43e..873b289a74 100644
--- a/tests/ApplicationDefaultCredentialsTest.php
+++ b/tests/ApplicationDefaultCredentialsTest.php
@@ -70,7 +70,7 @@ public function testLoadsOKIfEnvSpecifiedIsValid()
 
     public function testLoadsDefaultFileIfPresentAndEnvVarIsNotSet()
     {
-        putenv('HOME=' . __DIR__ . '/fixtures');
+        setHomeEnv(__DIR__ . '/fixtures');
         $this->assertNotNull(
             ApplicationDefaultCredentials::getCredentials('a scope')
         );
@@ -80,7 +80,7 @@ public function testFailsIfNotOnGceAndNoDefaultFileFound()
     {
         $this->expectException(DomainException::class);
 
-        putenv('HOME=' . __DIR__ . '/not_exist_fixtures');
+        setHomeEnv(__DIR__ . '/not_exist_fixtures');
         // simulate not being GCE and retry attempts by returning multiple 500s
         $httpHandler = getHandler([
             new Response(500),
@@ -93,7 +93,7 @@ public function testFailsIfNotOnGceAndNoDefaultFileFound()
 
     public function testSuccedsIfNoDefaultFilesButIsOnGCE()
     {
-        putenv('HOME');
+        setHomeEnv(null);
 
         $wantedTokens = [
             'access_token' => '1/abdef1234567890',
@@ -116,7 +116,7 @@ public function testSuccedsIfNoDefaultFilesButIsOnGCE()
 
     public function testGceCredentials()
     {
-        putenv('HOME');
+        setHomeEnv(null);
 
         $jsonTokens = json_encode(['access_token' => 'abc']);
 
@@ -160,7 +160,7 @@ public function testGceCredentials()
 
     public function testImpersonatedServiceAccountCredentials()
     {
-        putenv('HOME=' . __DIR__ . '/fixtures5');
+        setHomeEnv(__DIR__ . '/fixtures5');
         $creds = ApplicationDefaultCredentials::getCredentials(
             null,
             null,
@@ -183,7 +183,7 @@ public function testImpersonatedServiceAccountCredentials()
 
     public function testUserRefreshCredentials()
     {
-        putenv('HOME=' . __DIR__ . '/fixtures2');
+        setHomeEnv(__DIR__ . '/fixtures2');
 
         $creds = ApplicationDefaultCredentials::getCredentials(
             null, // $scope
@@ -219,7 +219,7 @@ public function testUserRefreshCredentials()
 
     public function testServiceAccountCredentials()
     {
-        putenv('HOME=' . __DIR__ . '/fixtures');
+        setHomeEnv(__DIR__ . '/fixtures');
 
         $creds = ApplicationDefaultCredentials::getCredentials(
             null, // $scope
@@ -255,7 +255,7 @@ public function testServiceAccountCredentials()
 
     public function testDefaultScopeArray()
     {
-        putenv('HOME=' . __DIR__ . '/fixtures2');
+        setHomeEnv(__DIR__ . '/fixtures2');
 
         $creds = ApplicationDefaultCredentials::getCredentials(
             null, // $scope
@@ -292,7 +292,7 @@ public function testGetMiddlewareLoadsOKIfEnvSpecifiedIsValid()
 
     public function testLGetMiddlewareoadsDefaultFileIfPresentAndEnvVarIsNotSet()
     {
-        putenv('HOME=' . __DIR__ . '/fixtures');
+        setHomeEnv(__DIR__ . '/fixtures');
         $this->assertNotNull(ApplicationDefaultCredentials::getMiddleware('a scope'));
     }
 
@@ -300,7 +300,7 @@ public function testGetMiddlewareFailsIfNotOnGceAndNoDefaultFileFound()
     {
         $this->expectException(DomainException::class);
 
-        putenv('HOME=' . __DIR__ . '/not_exist_fixtures');
+        setHomeEnv(__DIR__ . '/not_exist_fixtures');
 
         // simulate not being GCE and retry attempts by returning multiple 500s
         $httpHandler = getHandler([
@@ -356,7 +356,7 @@ public function testOnGceCacheWithHit()
     {
         $this->expectException(DomainException::class);
 
-        putenv('HOME=' . __DIR__ . '/not_exist_fixtures');
+        setHomeEnv(__DIR__ . '/not_exist_fixtures');
 
         $mockCacheItem = $this->prophesize('Psr\Cache\CacheItemInterface');
         $mockCacheItem->isHit()
@@ -380,7 +380,7 @@ public function testOnGceCacheWithHit()
 
     public function testOnGceCacheWithoutHit()
     {
-        putenv('HOME=' . __DIR__ . '/not_exist_fixtures');
+        setHomeEnv(__DIR__ . '/not_exist_fixtures');
 
         $gceIsCalled = false;
         $dummyHandler = function ($request) use (&$gceIsCalled) {
@@ -416,7 +416,7 @@ public function testOnGceCacheWithoutHit()
 
     public function testOnGceCacheWithOptions()
     {
-        putenv('HOME=' . __DIR__ . '/not_exist_fixtures');
+        setHomeEnv(__DIR__ . '/not_exist_fixtures');
 
         $prefix = 'test_prefix_';
         $lifetime = '70707';
@@ -473,7 +473,7 @@ public function testGetIdTokenCredentialsLoadsOKIfEnvSpecifiedIsValid()
 
     public function testGetIdTokenCredentialsLoadsDefaultFileIfPresentAndEnvVarIsNotSet()
     {
-        putenv('HOME=' . __DIR__ . '/fixtures');
+        setHomeEnv(__DIR__ . '/fixtures');
         $creds = ApplicationDefaultCredentials::getIdTokenCredentials($this->targetAudience);
         $this->assertInstanceOf(ServiceAccountCredentials::class, $creds);
     }
@@ -483,7 +483,7 @@ public function testGetIdTokenCredentialsFailsIfNotOnGceAndNoDefaultFileFound()
         $this->expectException(DomainException::class);
         $this->expectExceptionMessage('Your default credentials were not found');
 
-        putenv('HOME=' . __DIR__ . '/not_exist_fixtures');
+        setHomeEnv(__DIR__ . '/not_exist_fixtures');
 
         // simulate not being GCE and retry attempts by returning multiple 500s
         $httpHandler = getHandler([
@@ -500,7 +500,7 @@ public function testGetIdTokenCredentialsFailsIfNotOnGceAndNoDefaultFileFound()
 
     public function testGetIdTokenCredentialsWithImpersonatedServiceAccountCredentials()
     {
-        putenv('HOME=' . __DIR__ . '/fixtures5');
+        setHomeEnv(__DIR__ . '/fixtures5');
         $creds = ApplicationDefaultCredentials::getIdTokenCredentials('123@456.com');
         $this->assertInstanceOf(ImpersonatedServiceAccountCredentials::class, $creds);
     }
@@ -529,7 +529,7 @@ public function testGetIdTokenCredentialsWithCacheOptions()
 
     public function testGetIdTokenCredentialsSuccedsIfNoDefaultFilesButIsOnGCE()
     {
-        putenv('HOME=' . __DIR__ . '/not_exist_fixtures');
+        setHomeEnv(__DIR__ . '/not_exist_fixtures');
         $wantedTokens = [
             'access_token' => '1/abdef1234567890',
             'expires_in' => '57',
@@ -553,7 +553,7 @@ public function testGetIdTokenCredentialsSuccedsIfNoDefaultFilesButIsOnGCE()
 
     public function testGetIdTokenCredentialsWithUserRefreshCredentials()
     {
-        putenv('HOME=' . __DIR__ . '/fixtures2');
+        setHomeEnv(__DIR__ . '/fixtures2');
 
         $creds = ApplicationDefaultCredentials::getIdTokenCredentials(
             $this->targetAudience,
@@ -610,7 +610,7 @@ public function testGetCredentialsUtilizesQuotaProjectEnvVar()
     {
         $quotaProject = 'quota-project-from-env-var';
         putenv(CredentialsLoader::QUOTA_PROJECT_ENV_VAR . '=' . $quotaProject);
-        putenv('HOME=' . __DIR__ . '/fixtures');
+        setHomeEnv(__DIR__ . '/fixtures');
 
         $credentials = ApplicationDefaultCredentials::getCredentials();
 
@@ -625,7 +625,7 @@ public function testGetCredentialsUtilizesQuotaProjectParameterOverEnvVar()
     {
         $quotaProject = 'quota-project-from-parameter';
         putenv(CredentialsLoader::QUOTA_PROJECT_ENV_VAR . '=quota-project-from-env-var');
-        putenv('HOME=' . __DIR__ . '/fixtures');
+        setHomeEnv(__DIR__ . '/fixtures');
 
         $credentials = ApplicationDefaultCredentials::getCredentials(
             null, // $scope
@@ -688,7 +688,7 @@ public function testWithFetchAuthTokenCacheAndExplicitQuotaProject()
 
     public function testWithGCECredentials()
     {
-        putenv('HOME=' . __DIR__ . '/not_exist_fixtures');
+        setHomeEnv(__DIR__ . '/not_exist_fixtures');
         $wantedTokens = [
             'access_token' => '1/abdef1234567890',
             'expires_in' => '57',
@@ -721,7 +721,7 @@ public function testWithGCECredentials()
     public function testAppEngineStandard()
     {
         $_SERVER['SERVER_SOFTWARE'] = 'Google App Engine';
-        putenv('HOME=' . __DIR__ . '/not_exist_fixtures');
+        setHomeEnv(__DIR__ . '/not_exist_fixtures');
         $this->assertInstanceOf(
             'Google\Auth\Credentials\AppIdentityCredentials',
             ApplicationDefaultCredentials::getCredentials()
@@ -732,7 +732,7 @@ public function testAppEngineFlexible()
     {
         $_SERVER['SERVER_SOFTWARE'] = 'Google App Engine';
         putenv('GAE_INSTANCE=aef-default-20180313t154438');
-        putenv('HOME=' . __DIR__ . '/not_exist_fixtures');
+        setHomeEnv(__DIR__ . '/not_exist_fixtures');
         $httpHandler = getHandler([
             new Response(200, [GCECredentials::FLAVOR_HEADER => 'Google']),
         ]);
@@ -746,7 +746,7 @@ public function testAppEngineFlexibleIdToken()
     {
         $_SERVER['SERVER_SOFTWARE'] = 'Google App Engine';
         putenv('GAE_INSTANCE=aef-default-20180313t154438');
-        putenv('HOME=' . __DIR__ . '/not_exist_fixtures');
+        setHomeEnv(__DIR__ . '/not_exist_fixtures');
         $httpHandler = getHandler([
             new Response(200, [GCECredentials::FLAVOR_HEADER => 'Google']),
         ]);
@@ -868,7 +868,7 @@ public function testUniverseDomainInKeyFile()
     /** @runInSeparateProcess */
     public function testUniverseDomainInGceCredentials()
     {
-        putenv('HOME');
+        setHomeEnv(null);
 
         $expectedUniverseDomain = 'example-universe.com';
         $creds = ApplicationDefaultCredentials::getCredentials(
diff --git a/tests/Credentials/ExternalAccountCredentialsTest.php b/tests/Credentials/ExternalAccountCredentialsTest.php
index 3cade03037..60149b7970 100644
--- a/tests/Credentials/ExternalAccountCredentialsTest.php
+++ b/tests/Credentials/ExternalAccountCredentialsTest.php
@@ -586,7 +586,12 @@ public function testExecutableSourceCacheKey()
      */
     public function testExecutableCredentialSourceEnvironmentVars()
     {
+        if (PHP_OS_FAMILY === 'Windows') {
+            $this->markTestSkipped('This test does not work on Windows');
+        }
+
         putenv('GOOGLE_EXTERNAL_ACCOUNT_ALLOW_EXECUTABLES=1');
+
         $tmpFile = tempnam(sys_get_temp_dir(), 'test');
         $outputFile = tempnam(sys_get_temp_dir(), 'output');
         $fileContents = 'foo-' . rand();
@@ -597,20 +602,23 @@ public function testExecutableCredentialSourceEnvironmentVars()
             'id_token' => 'abc',
             'expiration_time' => time() + 100,
         ]);
+
+        $command = sprintf(
+            'echo $GOOGLE_EXTERNAL_ACCOUNT_AUDIENCE,$GOOGLE_EXTERNAL_ACCOUNT_TOKEN_TYPE,%s > %s' .
+            ' && echo \'%s\' > $GOOGLE_EXTERNAL_ACCOUNT_OUTPUT_FILE' .
+            ' && echo \'%s\'',
+            $fileContents,
+            $tmpFile,
+            $successJson,
+            $successJson
+        );
+
         $json = [
             'audience' => 'test-audience',
             'subject_token_type' => 'test-token-type',
             'credential_source' => [
                 'executable' => [
-                    'command' => sprintf(
-                        'echo $GOOGLE_EXTERNAL_ACCOUNT_AUDIENCE,$GOOGLE_EXTERNAL_ACCOUNT_TOKEN_TYPE,%s > %s' .
-                        ' && echo \'%s\' > $GOOGLE_EXTERNAL_ACCOUNT_OUTPUT_FILE ' .
-                        ' && echo \'%s\'',
-                        $fileContents,
-                        $tmpFile,
-                        $successJson,
-                        $successJson,
-                    ),
+                    'command' => $command,
                     'timeout_millis' => 5000,
                     'output_file' => $outputFile,
                 ],
diff --git a/tests/Credentials/ServiceAccountCredentialsTest.php b/tests/Credentials/ServiceAccountCredentialsTest.php
index 63110448e8..3af95e939a 100644
--- a/tests/Credentials/ServiceAccountCredentialsTest.php
+++ b/tests/Credentials/ServiceAccountCredentialsTest.php
@@ -192,7 +192,7 @@ public function testSucceedIfFileExists()
     /** @runInSeparateProcess */
     public function testIsNullIfFileDoesNotExist()
     {
-        putenv('HOME=' . __DIR__ . '/../not_exists_fixtures');
+        setHomeEnv(__DIR__ . '/../not_exists_fixtures');
         $this->assertNull(
             ServiceAccountCredentials::fromWellKnownFile()
         );
@@ -201,7 +201,7 @@ public function testIsNullIfFileDoesNotExist()
     /** @runInSeparateProcess */
     public function testSucceedIfFileIsPresent()
     {
-        putenv('HOME=' . __DIR__ . '/../fixtures');
+        setHomeEnv(__DIR__ . '/../fixtures');
         $this->assertNotNull(
             ApplicationDefaultCredentials::getCredentials('a scope')
         );
diff --git a/tests/Credentials/UserRefreshCredentialsTest.php b/tests/Credentials/UserRefreshCredentialsTest.php
index 7a8f393b90..0432182492 100644
--- a/tests/Credentials/UserRefreshCredentialsTest.php
+++ b/tests/Credentials/UserRefreshCredentialsTest.php
@@ -40,7 +40,7 @@ protected function tearDown(): void
     {
         putenv(UserRefreshCredentials::ENV_VAR);  // removes it from
         if ($this->originalHome != getenv('HOME')) {
-            putenv('HOME=' . $this->originalHome);
+            setHomeEnv($this->originalHome);
         }
     }
 
@@ -179,7 +179,7 @@ public function testSucceedIfFileExists()
 
     public function testIsNullIfFileDoesNotExist()
     {
-        putenv('HOME=' . __DIR__ . '/../not_exist_fixtures');
+        setHomeEnv(__DIR__ . '/../not_exist_fixtures');
         $this->assertNull(
             UserRefreshCredentials::fromWellKnownFile('a scope')
         );
@@ -187,7 +187,7 @@ public function testIsNullIfFileDoesNotExist()
 
     public function testSucceedIfFileIsPresent()
     {
-        putenv('HOME=' . __DIR__ . '/../fixtures2');
+        setHomeEnv(__DIR__ . '/../fixtures2');
         $this->assertNotNull(
             ApplicationDefaultCredentials::getCredentials('a scope')
         );
diff --git a/tests/CredentialsLoaderTest.php b/tests/CredentialsLoaderTest.php
index dcf257b765..d0336766c5 100644
--- a/tests/CredentialsLoaderTest.php
+++ b/tests/CredentialsLoaderTest.php
@@ -35,7 +35,7 @@ public function testUpdateMetadataSkipsWhenAuthenticationisSet()
     /** @runInSeparateProcess */
     public function testGetDefaultClientCertSource()
     {
-        putenv('HOME=' . __DIR__ . '/fixtures4/valid');
+        setHomeEnv(__DIR__ . '/fixtures4/valid');
 
         $callback = CredentialsLoader::getDefaultClientCertSource();
         $this->assertNotNull($callback);
@@ -47,7 +47,7 @@ public function testGetDefaultClientCertSource()
     /** @runInSeparateProcess */
     public function testNonExistantDefaultClientCertSource()
     {
-        putenv('HOME=');
+        setHomeEnv(null);
 
         $callback = CredentialsLoader::getDefaultClientCertSource();
         $this->assertNull($callback);
@@ -61,7 +61,7 @@ public function testDefaultClientCertSourceInvalidJsonThrowsException()
         $this->expectException(UnexpectedValueException::class);
         $this->expectExceptionMessage('Invalid client cert source JSON');
 
-        putenv('HOME=' . __DIR__ . '/fixtures4/invalidjson');
+        setHomeEnv(__DIR__ . '/fixtures4/invalidjson');
 
         CredentialsLoader::getDefaultClientCertSource();
     }
@@ -74,7 +74,7 @@ public function testDefaultClientCertSourceInvalidKeyThrowsException()
         $this->expectException(UnexpectedValueException::class);
         $this->expectExceptionMessage('cert source requires "cert_provider_command"');
 
-        putenv('HOME=' . __DIR__ . '/fixtures4/invalidkey');
+        setHomeEnv(__DIR__ . '/fixtures4/invalidkey');
 
         CredentialsLoader::getDefaultClientCertSource();
     }
@@ -87,7 +87,7 @@ public function testDefaultClientCertSourceInvalidValueThrowsException()
         $this->expectException(UnexpectedValueException::class);
         $this->expectExceptionMessage('cert source expects "cert_provider_command" to be an array');
 
-        putenv('HOME=' . __DIR__ . '/fixtures4/invalidvalue');
+        setHomeEnv(__DIR__ . '/fixtures4/invalidvalue');
 
         CredentialsLoader::getDefaultClientCertSource();
     }
@@ -115,7 +115,7 @@ public function testDefaultClientCertSourceInvalidCmdThrowsException()
         $this->expectException(RuntimeException::class);
         $this->expectExceptionMessage('"cert_provider_command" failed with a nonzero exit code');
 
-        putenv('HOME=' . __DIR__ . '/fixtures4/invalidcmd');
+        setHomeEnv(__DIR__ . '/fixtures4/invalidcmd');
 
         $callback = CredentialsLoader::getDefaultClientCertSource();
 
diff --git a/tests/ExecutableHandler/ExecutableHandlerTest.php b/tests/ExecutableHandler/ExecutableHandlerTest.php
index 16a3537db2..7561a4b546 100644
--- a/tests/ExecutableHandler/ExecutableHandlerTest.php
+++ b/tests/ExecutableHandler/ExecutableHandlerTest.php
@@ -26,17 +26,17 @@ class ExecutableHandlerTest extends TestCase
     public function testEnvironmentVariables()
     {
         $handler = new ExecutableHandler(['ENV_VAR_1' => 'foo', 'ENV_VAR_2' => 'bar']);
-        $this->assertEquals(0, $handler('echo $ENV_VAR_1'));
+        $this->assertEquals(0, $handler('bash -c "echo $ENV_VAR_1"'));
         $this->assertEquals("foo\n", $handler->getOutput());
 
-        $this->assertEquals(0, $handler('echo $ENV_VAR_2'));
+        $this->assertEquals(0, $handler('bash -c "echo $ENV_VAR_2"'));
         $this->assertEquals("bar\n", $handler->getOutput());
     }
 
     public function testTimeoutMs()
     {
-        $handler = new ExecutableHandler([], 300);
-        $this->assertEquals(0, $handler('sleep "0.2"'));
+        $handler = new ExecutableHandler([], 3000);
+        $this->assertEquals(0, $handler('bash -c \'sleep "0.1"\''));
     }
 
     public function testTimeoutMsExceeded()
@@ -51,7 +51,7 @@ public function testTimeoutMsExceeded()
     public function testErrorOutputIsReturnedAsOutput()
     {
         $handler = new ExecutableHandler();
-        $this->assertEquals(0, $handler('echo "Bad Response." >&2'));
+        $this->assertEquals(0, $handler('bash -c \'echo "Bad Response." >&2\''));
         $this->assertEquals("Bad Response.\n", $handler->getOutput());
     }
 }
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index e15bbb6290..e62b42ee22 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -28,3 +28,15 @@ function getHandler(array $mockResponses = [])
 
     return new \Google\Auth\HttpHandler\Guzzle6HttpHandler($client);
 }
+
+function setHomeEnv(string|null $value): void
+{
+    $assigment = sprintf(
+        '%s%s%s',
+        PHP_OS_FAMILY === 'Windows' ? 'APPDATA' : 'HOME',
+        $value === null ? '' : '=',
+        (string) $value
+    );
+
+    putenv($assigment);
+}
diff --git a/tests/fixtures/.config/gcloud b/tests/fixtures/.config/gcloud
new file mode 120000
index 0000000000..38d21f0a3c
--- /dev/null
+++ b/tests/fixtures/.config/gcloud
@@ -0,0 +1 @@
+../gcloud/
\ No newline at end of file
diff --git a/tests/fixtures/.config/gcloud/application_default_credentials.json b/tests/fixtures/gcloud/application_default_credentials.json
similarity index 100%
rename from tests/fixtures/.config/gcloud/application_default_credentials.json
rename to tests/fixtures/gcloud/application_default_credentials.json
diff --git a/tests/fixtures2/.config/gcloud b/tests/fixtures2/.config/gcloud
new file mode 120000
index 0000000000..38d21f0a3c
--- /dev/null
+++ b/tests/fixtures2/.config/gcloud
@@ -0,0 +1 @@
+../gcloud/
\ No newline at end of file
diff --git a/tests/fixtures2/.config/gcloud/application_default_credentials.json b/tests/fixtures2/gcloud/application_default_credentials.json
similarity index 100%
rename from tests/fixtures2/.config/gcloud/application_default_credentials.json
rename to tests/fixtures2/gcloud/application_default_credentials.json
diff --git a/tests/fixtures5/.config/gcloud b/tests/fixtures5/.config/gcloud
new file mode 120000
index 0000000000..38d21f0a3c
--- /dev/null
+++ b/tests/fixtures5/.config/gcloud
@@ -0,0 +1 @@
+../gcloud/
\ No newline at end of file
diff --git a/tests/fixtures5/.config/gcloud/application_default_credentials.json b/tests/fixtures5/gcloud/application_default_credentials.json
similarity index 100%
rename from tests/fixtures5/.config/gcloud/application_default_credentials.json
rename to tests/fixtures5/gcloud/application_default_credentials.json