diff --git a/harness/pstack/claude-code/skills/statechart/scripts/frontends/dot.ts b/harness/pstack/claude-code/skills/statechart/scripts/frontends/dot.ts
index 003dfc89d..32a41b7fa 100644
--- a/harness/pstack/claude-code/skills/statechart/scripts/frontends/dot.ts
+++ b/harness/pstack/claude-code/skills/statechart/scripts/frontends/dot.ts
@@ -35,7 +35,7 @@ export const parseState = (label: string, parsed = new Map<string, [string, Valu
 
 export type Lines = string | Iterable<string>;
 
-export const linesOf = (input: Lines) => (typeof input === "string" ? input.split("\n") : input);
+export const linesOf = (input: Lines) => (typeof input === "string" ? input.split(/\r?\n/) : input);
 
 export function parseDot(input: Lines): Graph {
   const states = new Map<string, State>();
diff --git a/harness/pstack/claude-code/skills/statechart/scripts/janitor.ts b/harness/pstack/claude-code/skills/statechart/scripts/janitor.ts
new file mode 100644
index 000000000..1e6674e10
--- /dev/null
+++ b/harness/pstack/claude-code/skills/statechart/scripts/janitor.ts
@@ -0,0 +1,11 @@
+import fs from "node:fs";
+import { killGroup } from "./run.ts";
+
+const [pid, ...dirs] = process.argv.slice(2);
+
+process.stdin
+  .on("end", async () => {
+    await killGroup(Number(pid));
+    for (const dir of dirs) fs.rmSync(dir, { recursive: true, force: true, maxRetries: 10 });
+  })
+  .resume();
diff --git a/harness/pstack/claude-code/skills/statechart/scripts/run.ts b/harness/pstack/claude-code/skills/statechart/scripts/run.ts
index 4efd368e5..4c003d666 100644
--- a/harness/pstack/claude-code/skills/statechart/scripts/run.ts
+++ b/harness/pstack/claude-code/skills/statechart/scripts/run.ts
@@ -55,7 +55,7 @@ export function* fileLines(file: string) {
         kept = end;
         continue;
       }
-      yield* buf.toString("utf8", 0, cut).split("\n");
+      yield* buf.toString("utf8", 0, buf[cut - 1] === 13 ? cut - 1 : cut).split(/\r?\n/);
       kept = buf.copy(buf, 0, cut + 1, end);
     }
     yield buf.toString("utf8", 0, kept);
@@ -81,7 +81,7 @@ const runChild = (file: string, args: string[], options: { cwd: string; env: Nod
     execFile(
       file,
       args,
-      { encoding: "utf8", maxBuffer: 1 << 30, ...options },
+      { encoding: "utf8", maxBuffer: 1 << 30, windowsHide: true, ...options },
       (error, stdout, stderr) =>
         resolve({
           status: error ? (typeof error.code === "number" ? error.code : null) : 0,
@@ -94,10 +94,10 @@ const runChild = (file: string, args: string[], options: { cwd: string; env: Nod
 
 export const killGroup = (pid: number) =>
   new Promise((resolve) =>
-    spawn("/bin/sh", ["-c", 'kill -s KILL -- "-$1"', "sh", String(pid)], { stdio: "ignore" }).on(
-      "exit",
-      resolve,
-    ),
+    (process.platform === "win32"
+      ? spawn("taskkill", ["/T", "/F", "/PID", String(pid)], { stdio: "ignore", windowsHide: true })
+      : spawn("/bin/sh", ["-c", 'kill -s KILL -- "-$1"', "sh", String(pid)], { stdio: "ignore" })
+    ).on("exit", resolve),
   );
 
 export const messageOf = (error: unknown) =>
@@ -141,7 +141,7 @@ function* outputLines(output: Output) {
       rest = buf;
       continue;
     }
-    yield* utf8.decode(buf.subarray(0, cut)).split("\n");
+    yield* utf8.decode(buf.subarray(0, buf[cut - 1] === 13 ? cut - 1 : cut)).split(/\r?\n/);
     rest = buf.subarray(cut + 1);
   }
   yield utf8.decode(rest);
@@ -169,7 +169,7 @@ const runToFiles = (
     for (const f of files) fds.push(fs.openSync(f, "w"));
     let child: ChildProcess;
     try {
-      child = spawn(file, args, { ...options, stdio: ["ignore", ...fds] });
+      child = spawn(file, args, { ...options, stdio: ["ignore", ...fds], windowsHide: true });
     } finally {
       for (const fd of fds) fs.closeSync(fd);
     }
diff --git a/harness/pstack/claude-code/skills/statechart/scripts/statechart.ts b/harness/pstack/claude-code/skills/statechart/scripts/statechart.ts
index 4e2967e68..d2919c6e9 100644
--- a/harness/pstack/claude-code/skills/statechart/scripts/statechart.ts
+++ b/harness/pstack/claude-code/skills/statechart/scripts/statechart.ts
@@ -110,26 +110,40 @@ try {
       {
         detached: true,
         stdio: ["ignore", "inherit", "inherit"],
-        env: { ...process.env, TMPDIR: tmp },
+        env: { ...process.env, TMPDIR: tmp, TEMP: tmp, TMP: tmp },
       },
     );
-    janitor = spawn(
-      "/bin/sh",
-      [
-        "-c",
-        'while read -r line; do :; done; kill -s KILL -- "-$1"; rm -rf -- "$2" "$3"',
-        "sh",
-        String(worker.pid),
-        stage,
-        tmp,
-      ],
-      { detached: true, stdio: ["pipe", "ignore", "ignore"] },
-    );
+    janitor =
+      process.platform === "win32"
+        ? spawn(
+            process.execPath,
+            [
+              ...runtime,
+              path.join(import.meta.dirname, "janitor.ts"),
+              String(worker.pid),
+              stage,
+              tmp,
+            ],
+            { detached: true, stdio: ["pipe", "ignore", "ignore"] },
+          )
+        : spawn(
+            "/bin/sh",
+            [
+              "-c",
+              'while read -r line; do :; done; kill -s KILL -- "-$1"; rm -rf -- "$2" "$3"',
+              "sh",
+              String(worker.pid),
+              stage,
+              tmp,
+            ],
+            { detached: true, stdio: ["pipe", "ignore", "ignore"] },
+          );
     const exited = new Promise<number>((resolve) =>
       worker.on("exit", (code) => resolve(code ?? 2)),
     );
     await Promise.race([stopped, exited]);
-    await killGroup(worker.pid as number);
+    if (process.platform !== "win32" || worker.exitCode === null)
+      await killGroup(worker.pid as number);
     const verdict = await exited;
     if (stop) {
       console.error(`${stop} stopped the check, so the command wrote nothing.`);
diff --git a/harness/pstack/claude-code/skills/statechart/scripts/test/cli.test.ts b/harness/pstack/claude-code/skills/statechart/scripts/test/cli.test.ts
index 97b71c30c..02e02e497 100644
--- a/harness/pstack/claude-code/skills/statechart/scripts/test/cli.test.ts
+++ b/harness/pstack/claude-code/skills/statechart/scripts/test/cli.test.ts
@@ -217,6 +217,24 @@ test("the order of TLC's dump and its state IDs do not change the chart or the r
   }
 });
 
+test("TLC's output with CRLF line ends, as Java prints it on Windows, does not change the chart or the report", () => {
+  for (const name of ["DieHard", "MediaPlayer", "MediaPlayerProps"]) {
+    const dir = copyCase(name, (d) => {
+      for (const f of fs.readdirSync(d))
+        if (/\.(out|dot)$/.test(f))
+          fs.writeFileSync(path.join(d, f), read(path.join(d, f)).replace(/\r?\n/g, "\r\n"));
+    });
+    const r = run(dir);
+    assert.equal(r.stderr, "", name);
+    assert.equal(r.report, read(path.join(corpus, name, "report.md")), name);
+    assert.equal(
+      read(path.join(r.out, "chart.mmd")),
+      read(path.join(corpus, name, "chart.mmd")),
+      name,
+    );
+  }
+});
+
 function startCommand(
   dir: string,
   parent: string,
diff --git a/pstack/skills/statechart/scripts/frontends/dot.ts b/pstack/skills/statechart/scripts/frontends/dot.ts
index 003dfc89d..32a41b7fa 100644
--- a/pstack/skills/statechart/scripts/frontends/dot.ts
+++ b/pstack/skills/statechart/scripts/frontends/dot.ts
@@ -35,7 +35,7 @@ export const parseState = (label: string, parsed = new Map<string, [string, Valu
 
 export type Lines = string | Iterable<string>;
 
-export const linesOf = (input: Lines) => (typeof input === "string" ? input.split("\n") : input);
+export const linesOf = (input: Lines) => (typeof input === "string" ? input.split(/\r?\n/) : input);
 
 export function parseDot(input: Lines): Graph {
   const states = new Map<string, State>();
diff --git a/pstack/skills/statechart/scripts/janitor.ts b/pstack/skills/statechart/scripts/janitor.ts
new file mode 100644
index 000000000..1e6674e10
--- /dev/null
+++ b/pstack/skills/statechart/scripts/janitor.ts
@@ -0,0 +1,11 @@
+import fs from "node:fs";
+import { killGroup } from "./run.ts";
+
+const [pid, ...dirs] = process.argv.slice(2);
+
+process.stdin
+  .on("end", async () => {
+    await killGroup(Number(pid));
+    for (const dir of dirs) fs.rmSync(dir, { recursive: true, force: true, maxRetries: 10 });
+  })
+  .resume();
diff --git a/pstack/skills/statechart/scripts/run.ts b/pstack/skills/statechart/scripts/run.ts
index 4efd368e5..4c003d666 100644
--- a/pstack/skills/statechart/scripts/run.ts
+++ b/pstack/skills/statechart/scripts/run.ts
@@ -55,7 +55,7 @@ export function* fileLines(file: string) {
         kept = end;
         continue;
       }
-      yield* buf.toString("utf8", 0, cut).split("\n");
+      yield* buf.toString("utf8", 0, buf[cut - 1] === 13 ? cut - 1 : cut).split(/\r?\n/);
       kept = buf.copy(buf, 0, cut + 1, end);
     }
     yield buf.toString("utf8", 0, kept);
@@ -81,7 +81,7 @@ const runChild = (file: string, args: string[], options: { cwd: string; env: Nod
     execFile(
       file,
       args,
-      { encoding: "utf8", maxBuffer: 1 << 30, ...options },
+      { encoding: "utf8", maxBuffer: 1 << 30, windowsHide: true, ...options },
       (error, stdout, stderr) =>
         resolve({
           status: error ? (typeof error.code === "number" ? error.code : null) : 0,
@@ -94,10 +94,10 @@ const runChild = (file: string, args: string[], options: { cwd: string; env: Nod
 
 export const killGroup = (pid: number) =>
   new Promise((resolve) =>
-    spawn("/bin/sh", ["-c", 'kill -s KILL -- "-$1"', "sh", String(pid)], { stdio: "ignore" }).on(
-      "exit",
-      resolve,
-    ),
+    (process.platform === "win32"
+      ? spawn("taskkill", ["/T", "/F", "/PID", String(pid)], { stdio: "ignore", windowsHide: true })
+      : spawn("/bin/sh", ["-c", 'kill -s KILL -- "-$1"', "sh", String(pid)], { stdio: "ignore" })
+    ).on("exit", resolve),
   );
 
 export const messageOf = (error: unknown) =>
@@ -141,7 +141,7 @@ function* outputLines(output: Output) {
       rest = buf;
       continue;
     }
-    yield* utf8.decode(buf.subarray(0, cut)).split("\n");
+    yield* utf8.decode(buf.subarray(0, buf[cut - 1] === 13 ? cut - 1 : cut)).split(/\r?\n/);
     rest = buf.subarray(cut + 1);
   }
   yield utf8.decode(rest);
@@ -169,7 +169,7 @@ const runToFiles = (
     for (const f of files) fds.push(fs.openSync(f, "w"));
     let child: ChildProcess;
     try {
-      child = spawn(file, args, { ...options, stdio: ["ignore", ...fds] });
+      child = spawn(file, args, { ...options, stdio: ["ignore", ...fds], windowsHide: true });
     } finally {
       for (const fd of fds) fs.closeSync(fd);
     }
diff --git a/pstack/skills/statechart/scripts/statechart.ts b/pstack/skills/statechart/scripts/statechart.ts
index 4e2967e68..d2919c6e9 100644
--- a/pstack/skills/statechart/scripts/statechart.ts
+++ b/pstack/skills/statechart/scripts/statechart.ts
@@ -110,26 +110,40 @@ try {
       {
         detached: true,
         stdio: ["ignore", "inherit", "inherit"],
-        env: { ...process.env, TMPDIR: tmp },
+        env: { ...process.env, TMPDIR: tmp, TEMP: tmp, TMP: tmp },
       },
     );
-    janitor = spawn(
-      "/bin/sh",
-      [
-        "-c",
-        'while read -r line; do :; done; kill -s KILL -- "-$1"; rm -rf -- "$2" "$3"',
-        "sh",
-        String(worker.pid),
-        stage,
-        tmp,
-      ],
-      { detached: true, stdio: ["pipe", "ignore", "ignore"] },
-    );
+    janitor =
+      process.platform === "win32"
+        ? spawn(
+            process.execPath,
+            [
+              ...runtime,
+              path.join(import.meta.dirname, "janitor.ts"),
+              String(worker.pid),
+              stage,
+              tmp,
+            ],
+            { detached: true, stdio: ["pipe", "ignore", "ignore"] },
+          )
+        : spawn(
+            "/bin/sh",
+            [
+              "-c",
+              'while read -r line; do :; done; kill -s KILL -- "-$1"; rm -rf -- "$2" "$3"',
+              "sh",
+              String(worker.pid),
+              stage,
+              tmp,
+            ],
+            { detached: true, stdio: ["pipe", "ignore", "ignore"] },
+          );
     const exited = new Promise<number>((resolve) =>
       worker.on("exit", (code) => resolve(code ?? 2)),
     );
     await Promise.race([stopped, exited]);
-    await killGroup(worker.pid as number);
+    if (process.platform !== "win32" || worker.exitCode === null)
+      await killGroup(worker.pid as number);
     const verdict = await exited;
     if (stop) {
       console.error(`${stop} stopped the check, so the command wrote nothing.`);
diff --git a/pstack/skills/statechart/scripts/test/cli.test.ts b/pstack/skills/statechart/scripts/test/cli.test.ts
index 97b71c30c..02e02e497 100644
--- a/pstack/skills/statechart/scripts/test/cli.test.ts
+++ b/pstack/skills/statechart/scripts/test/cli.test.ts
@@ -217,6 +217,24 @@ test("the order of TLC's dump and its state IDs do not change the chart or the r
   }
 });
 
+test("TLC's output with CRLF line ends, as Java prints it on Windows, does not change the chart or the report", () => {
+  for (const name of ["DieHard", "MediaPlayer", "MediaPlayerProps"]) {
+    const dir = copyCase(name, (d) => {
+      for (const f of fs.readdirSync(d))
+        if (/\.(out|dot)$/.test(f))
+          fs.writeFileSync(path.join(d, f), read(path.join(d, f)).replace(/\r?\n/g, "\r\n"));
+    });
+    const r = run(dir);
+    assert.equal(r.stderr, "", name);
+    assert.equal(r.report, read(path.join(corpus, name, "report.md")), name);
+    assert.equal(
+      read(path.join(r.out, "chart.mmd")),
+      read(path.join(corpus, name, "chart.mmd")),
+      name,
+    );
+  }
+});
+
 function startCommand(
   dir: string,
   parent: string,