diff --git a/changelog.d/fixes/10244-cliproxy-installer-windows-platform-detection.md b/changelog.d/fixes/10244-cliproxy-installer-windows-platform-detection.md
new file mode 100644
index 0000000000..bdc134b990
--- /dev/null
+++ b/changelog.d/fixes/10244-cliproxy-installer-windows-platform-detection.md
@@ -0,0 +1 @@
+- **fix(cliproxy):** read platform/arch at runtime via `os.platform()`/`os.arch()` in `binaryManager` so the embedded installer selects the Windows/ARM assets even when the release bundle is built on a Linux runner (fixes #10244)
\ No newline at end of file
diff --git a/src/lib/versionManager/binaryManager.ts b/src/lib/versionManager/binaryManager.ts
index eec36ab3cb..c77ac0a79f 100644
--- a/src/lib/versionManager/binaryManager.ts
+++ b/src/lib/versionManager/binaryManager.ts
@@ -16,7 +16,7 @@ type Platform = "linux" | "darwin" | "windows" | "freebsd";
 type Arch = "amd64" | "arm64";
 
 function detectPlatform(): Platform {
-  const p = process.platform;
+  const p = os.platform();
   if (p === "linux") return "linux";
   if (p === "darwin") return "darwin";
   if (p === "win32") return "windows";
@@ -24,7 +24,7 @@ function detectPlatform(): Platform {
 }
 
 function detectArch(): Arch {
-  const a = process.arch;
+  const a = os.arch();
   if (a === "x64") return "amd64";
   if (a === "arm64") return "arm64";
   return "amd64";
diff --git a/tests/unit/binaryManager.test.ts b/tests/unit/binaryManager.test.ts
index dd0acba78b..188bcc3348 100644
--- a/tests/unit/binaryManager.test.ts
+++ b/tests/unit/binaryManager.test.ts
@@ -1,4 +1,4 @@
-import { describe, it, afterEach, after } from "node:test";
+import { describe, it, afterEach, after, mock } from "node:test";
 import assert from "node:assert/strict";
 import path from "node:path";
 import fs from "node:fs";
@@ -63,6 +63,22 @@ describe("binaryManager", () => {
       assert.ok(["linux", "darwin", "windows"].includes(platform));
       assert.ok(["amd64", "arm64"].includes(arch));
     });
+
+    it("should read platform/arch at runtime from os (anti build-folding guard) (#10244)", () => {
+      // Regression guard for #10244/#10293: detectPlatform/detectArch must read
+      // os.platform()/os.arch() at call time, NOT the build-machine foldable
+      // process.platform/process.arch constants. Turbopack `next build` running
+      // on Linux constant-folds `process.platform` and prunes every Windows/arm64
+      // branch from the published npm artifact. Simulate a Windows arm64 host via
+      // the runtime os.* functions; the Windows/arm64 branch must be reachable.
+      mock.method(os, "platform", () => "win32");
+      mock.method(os, "arch", () => "arm64");
+      assert.deepEqual(mod.getTargetPlatform(), { platform: "windows", arch: "arm64" });
+      assert.equal(
+        mod.getAssetName(),
+        "CLIProxyAPI_{version}_windows_arm64.zip"
+      );
+    });
   });
 
   describe("getCurrentBinaryPath", () => {