diff --git a/scripts/test-group-report.mjs b/scripts/test-group-report.mjs
index 78abc7ae31ce..29627b71cec4 100644
--- a/scripts/test-group-report.mjs
+++ b/scripts/test-group-report.mjs
@@ -263,6 +263,12 @@ export function signalTestGroupReportChild(
     if (!result?.error && result?.status === 0) {
       return;
     }
+    if (signal !== "SIGKILL") {
+      const forceResult = runTaskkill("taskkill", [...args, "/F"], { stdio: "ignore" });
+      if (!forceResult?.error && forceResult?.status === 0) {
+        return;
+      }
+    }
   }
   child.kill(signal);
 }
diff --git a/test/scripts/test-group-report.test.ts b/test/scripts/test-group-report.test.ts
index cae4586f8267..6ae52f04801a 100644
--- a/test/scripts/test-group-report.test.ts
+++ b/test/scripts/test-group-report.test.ts
@@ -636,6 +636,30 @@ describe("scripts/test-group-report child process guard", () => {
     expect(child.kill).not.toHaveBeenCalled();
   });
 
+  it("force-kills Windows child process trees when graceful taskkill fails", () => {
+    const child = {
+      kill: vi.fn(),
+      pid: 12345,
+    };
+    const runTaskkill = vi
+      .fn()
+      .mockReturnValueOnce({ error: undefined, status: 1 })
+      .mockReturnValueOnce({ error: undefined, status: 0 });
+
+    signalTestGroupReportChild(child, "SIGTERM", {
+      platform: "win32",
+      runTaskkill,
+    });
+
+    expect(runTaskkill).toHaveBeenNthCalledWith(1, "taskkill", ["/PID", "12345", "/T"], {
+      stdio: "ignore",
+    });
+    expect(runTaskkill).toHaveBeenNthCalledWith(2, "taskkill", ["/PID", "12345", "/T", "/F"], {
+      stdio: "ignore",
+    });
+    expect(child.kill).not.toHaveBeenCalled();
+  });
+
   it("times out a child that ignores SIGTERM", async () => {
     if (process.platform === "win32") {
       return;