diff --git a/launcher/config/plugin-runtime-config.ts b/launcher/config/plugin-runtime-config.ts
index 06f8b10e..64498a14 100644
--- a/launcher/config/plugin-runtime-config.ts
+++ b/launcher/config/plugin-runtime-config.ts
@@ -5,6 +5,10 @@ import { log } from '../log.js';
 import type { LogLevel, PluginRuntimeConfig } from '../types.js';
 import { DEFAULT_SOCKET_PATH } from '../types.js';
 
+function getPlatformPath(platform: NodeJS.Platform): typeof path.posix | typeof path.win32 {
+  return platform === 'win32' ? path.win32 : path.posix;
+}
+
 export function getPluginConfigCandidates(options?: {
   platform?: NodeJS.Platform;
   homeDir?: string;
@@ -13,21 +17,24 @@ export function getPluginConfigCandidates(options?: {
 }): string[] {
   const platform = options?.platform ?? process.platform;
   const homeDir = options?.homeDir ?? os.homedir();
+  const platformPath = getPlatformPath(platform);
 
   if (platform === 'win32') {
     const appDataDir =
       options?.appDataDir?.trim() ||
       process.env.APPDATA?.trim() ||
-      path.join(homeDir, 'AppData', 'Roaming');
-    return [path.join(appDataDir, 'mpv', 'script-opts', 'subminer.conf')];
+      platformPath.join(homeDir, 'AppData', 'Roaming');
+    return [platformPath.join(appDataDir, 'mpv', 'script-opts', 'subminer.conf')];
   }
 
   const xdgConfigHome =
-    options?.xdgConfigHome?.trim() || process.env.XDG_CONFIG_HOME || path.join(homeDir, '.config');
+    options?.xdgConfigHome?.trim() ||
+    process.env.XDG_CONFIG_HOME ||
+    platformPath.join(homeDir, '.config');
   return Array.from(
     new Set([
-      path.join(xdgConfigHome, 'mpv', 'script-opts', 'subminer.conf'),
-      path.join(homeDir, '.config', 'mpv', 'script-opts', 'subminer.conf'),
+      platformPath.join(xdgConfigHome, 'mpv', 'script-opts', 'subminer.conf'),
+      platformPath.join(homeDir, '.config', 'mpv', 'script-opts', 'subminer.conf'),
     ]),
   );
 }
diff --git a/launcher/main.test.ts b/launcher/main.test.ts
index 8d7c2c65..236ba409 100644
--- a/launcher/main.test.ts
+++ b/launcher/main.test.ts
@@ -81,14 +81,14 @@ test('config path uses XDG_CONFIG_HOME override', () => {
 test('config discovery ignores lowercase subminer candidate', () => {
   const homeDir = '/home/tester';
   const xdgConfigHome = '/tmp/xdg-config';
-  const expected = path.join(xdgConfigHome, 'SubMiner', 'config.jsonc');
-  const foundPaths = new Set([path.join(xdgConfigHome, 'subminer', 'config.json')]);
+  const expected = path.posix.join(xdgConfigHome, 'SubMiner', 'config.jsonc');
+  const foundPaths = new Set([path.posix.join(xdgConfigHome, 'subminer', 'config.json')]);
 
   const resolved = resolveConfigFilePath({
     xdgConfigHome,
     homeDir,
     platform: 'linux',
-    existsSync: (candidate) => foundPaths.has(path.normalize(candidate)),
+    existsSync: (candidate) => foundPaths.has(path.posix.normalize(candidate)),
   });
 
   assert.equal(resolved, expected);
diff --git a/src/config/path-resolution.test.ts b/src/config/path-resolution.test.ts
index 15bfb78b..6be09f92 100644
--- a/src/config/path-resolution.test.ts
+++ b/src/config/path-resolution.test.ts
@@ -11,7 +11,7 @@ function existsSyncFrom(paths: string[]): (candidate: string) => boolean {
 test('resolveConfigBaseDirs trims xdg value and deduplicates fallback dir', () => {
   const homeDir = '/home/tester';
   const trimmedXdgConfigHome = '/home/tester/.config';
-  const fallbackDir = path.join(homeDir, '.config');
+  const fallbackDir = path.posix.join(homeDir, '.config');
   const baseDirs = resolveConfigBaseDirs(` ${trimmedXdgConfigHome} `, homeDir, 'linux');
   const expected = Array.from(new Set([trimmedXdgConfigHome, fallbackDir]));
   assert.deepEqual(baseDirs, expected);
@@ -29,8 +29,8 @@ test('resolveConfigBaseDirs prefers APPDATA on windows and deduplicates fallback
 test('resolveConfigDir prefers xdg SubMiner config when present', () => {
   const homeDir = '/home/tester';
   const xdgConfigHome = '/tmp/xdg-config';
-  const configDir = path.join(xdgConfigHome, 'SubMiner');
-  const existsSync = existsSyncFrom([path.join(configDir, 'config.jsonc')]);
+  const configDir = path.posix.join(xdgConfigHome, 'SubMiner');
+  const existsSync = existsSyncFrom([path.posix.join(configDir, 'config.jsonc')]);
 
   const resolved = resolveConfigDir({
     xdgConfigHome,
@@ -54,12 +54,12 @@ test('resolveConfigDir ignores lowercase subminer candidate', () => {
     existsSync,
   });
 
-  assert.equal(resolved, path.join('/tmp/missing-xdg', 'SubMiner'));
+  assert.equal(resolved, path.posix.join('/tmp/missing-xdg', 'SubMiner'));
 });
 
 test('resolveConfigDir falls back to existing directory when file is missing', () => {
   const homeDir = '/home/tester';
-  const configDir = path.join(homeDir, '.config', 'SubMiner');
+  const configDir = path.posix.join(homeDir, '.config', 'SubMiner');
   const existsSync = existsSyncFrom([configDir]);
 
   const resolved = resolveConfigDir({
@@ -76,8 +76,8 @@ test('resolveConfigFilePath prefers jsonc before json', () => {
   const homeDir = '/home/tester';
   const xdgConfigHome = '/tmp/xdg-config';
   const existsSync = existsSyncFrom([
-    path.join(xdgConfigHome, 'SubMiner', 'config.jsonc'),
-    path.join(xdgConfigHome, 'SubMiner', 'config.json'),
+    path.posix.join(xdgConfigHome, 'SubMiner', 'config.jsonc'),
+    path.posix.join(xdgConfigHome, 'SubMiner', 'config.json'),
   ]);
 
   const resolved = resolveConfigFilePath({
@@ -87,7 +87,7 @@ test('resolveConfigFilePath prefers jsonc before json', () => {
     existsSync,
   });
 
-  assert.equal(resolved, path.join(xdgConfigHome, 'SubMiner', 'config.jsonc'));
+  assert.equal(resolved, path.posix.join(xdgConfigHome, 'SubMiner', 'config.jsonc'));
 });
 
 test('resolveConfigFilePath keeps legacy fallback output path', () => {
@@ -102,14 +102,14 @@ test('resolveConfigFilePath keeps legacy fallback output path', () => {
     existsSync,
   });
 
-  assert.equal(resolved, path.join(xdgConfigHome, 'SubMiner', 'config.jsonc'));
+  assert.equal(resolved, path.posix.join(xdgConfigHome, 'SubMiner', 'config.jsonc'));
 });
 
 test('resolveConfigDir prefers APPDATA SubMiner config on windows when present', () => {
   const homeDir = 'C:\\Users\\tester';
   const appDataDir = 'C:\\Users\\tester\\AppData\\Roaming';
-  const configDir = path.join(appDataDir, 'SubMiner');
-  const existsSync = existsSyncFrom([path.join(configDir, 'config.jsonc')]);
+  const configDir = path.win32.join(appDataDir, 'SubMiner');
+  const existsSync = existsSyncFrom([path.win32.join(configDir, 'config.jsonc')]);
 
   const resolved = resolveConfigDir({
     platform: 'win32',
@@ -133,5 +133,5 @@ test('resolveConfigFilePath uses APPDATA fallback output path on windows', () =>
     existsSync,
   });
 
-  assert.equal(resolved, path.join(appDataDir, 'SubMiner', 'config.jsonc'));
+  assert.equal(resolved, path.win32.join(appDataDir, 'SubMiner', 'config.jsonc'));
 });
diff --git a/src/config/path-resolution.ts b/src/config/path-resolution.ts
index 55dcba40..ad123c02 100644
--- a/src/config/path-resolution.ts
+++ b/src/config/path-resolution.ts
@@ -15,19 +15,24 @@ type ConfigPathOptions = {
 const DEFAULT_APP_NAMES = ['SubMiner'] as const;
 const DEFAULT_FILE_NAMES = ['config.jsonc', 'config.json'] as const;
 
+function getPlatformPath(platform: NodeJS.Platform): typeof path.posix | typeof path.win32 {
+  return platform === 'win32' ? path.win32 : path.posix;
+}
+
 export function resolveConfigBaseDirs(
   xdgConfigHome: string | undefined,
   homeDir: string,
   platform: NodeJS.Platform = process.platform,
   appDataDir?: string,
 ): string[] {
+  const platformPath = getPlatformPath(platform);
   if (platform === 'win32') {
-    const roamingBaseDir = path.join(homeDir, 'AppData', 'Roaming');
+    const roamingBaseDir = platformPath.join(homeDir, 'AppData', 'Roaming');
     const primaryBaseDir = appDataDir?.trim() || roamingBaseDir;
     return Array.from(new Set([primaryBaseDir, roamingBaseDir]));
   }
 
-  const fallbackBaseDir = path.join(homeDir, '.config');
+  const fallbackBaseDir = platformPath.join(homeDir, '.config');
   const primaryBaseDir = xdgConfigHome?.trim() || fallbackBaseDir;
   return Array.from(new Set([primaryBaseDir, fallbackBaseDir]));
 }
@@ -41,19 +46,21 @@ function getDefaultAppName(options: ConfigPathOptions): string {
 }
 
 export function resolveConfigDir(options: ConfigPathOptions): string {
+  const platform = options.platform ?? process.platform;
+  const platformPath = getPlatformPath(platform);
   const baseDirs = resolveConfigBaseDirs(
     options.xdgConfigHome,
     options.homeDir,
-    options.platform,
+    platform,
     options.appDataDir,
   );
   const appNames = getAppNames(options);
 
   for (const baseDir of baseDirs) {
     for (const appName of appNames) {
-      const dir = path.join(baseDir, appName);
+      const dir = platformPath.join(baseDir, appName);
       for (const fileName of DEFAULT_FILE_NAMES) {
-        if (options.existsSync(path.join(dir, fileName))) {
+        if (options.existsSync(platformPath.join(dir, fileName))) {
           return dir;
         }
       }
@@ -62,21 +69,23 @@ export function resolveConfigDir(options: ConfigPathOptions): string {
 
   for (const baseDir of baseDirs) {
     for (const appName of appNames) {
-      const dir = path.join(baseDir, appName);
+      const dir = platformPath.join(baseDir, appName);
       if (options.existsSync(dir)) {
         return dir;
       }
     }
   }
 
-  return path.join(baseDirs[0]!, getDefaultAppName(options));
+  return platformPath.join(baseDirs[0]!, getDefaultAppName(options));
 }
 
 export function resolveConfigFilePath(options: ConfigPathOptions): string {
+  const platform = options.platform ?? process.platform;
+  const platformPath = getPlatformPath(platform);
   const baseDirs = resolveConfigBaseDirs(
     options.xdgConfigHome,
     options.homeDir,
-    options.platform,
+    platform,
     options.appDataDir,
   );
   const appNames = getAppNames(options);
@@ -84,7 +93,7 @@ export function resolveConfigFilePath(options: ConfigPathOptions): string {
   for (const baseDir of baseDirs) {
     for (const appName of appNames) {
       for (const fileName of DEFAULT_FILE_NAMES) {
-        const candidate = path.join(baseDir, appName, fileName);
+        const candidate = platformPath.join(baseDir, appName, fileName);
         if (options.existsSync(candidate)) {
           return candidate;
         }
@@ -92,5 +101,5 @@ export function resolveConfigFilePath(options: ConfigPathOptions): string {
     }
   }
 
-  return path.join(baseDirs[0]!, getDefaultAppName(options), DEFAULT_FILE_NAMES[0]!);
+  return platformPath.join(baseDirs[0]!, getDefaultAppName(options), DEFAULT_FILE_NAMES[0]!);
 }
diff --git a/src/shared/setup-state.test.ts b/src/shared/setup-state.test.ts
index ca5905fc..97627f81 100644
--- a/src/shared/setup-state.test.ts
+++ b/src/shared/setup-state.test.ts
@@ -30,10 +30,11 @@ test('getDefaultConfigDir prefers existing SubMiner config directory', () => {
     platform: 'linux',
     xdgConfigHome,
     homeDir,
-    existsSync: (candidate) => candidate === path.join(xdgConfigHome, 'SubMiner', 'config.jsonc'),
+    existsSync: (candidate) =>
+      candidate === path.posix.join(xdgConfigHome, 'SubMiner', 'config.jsonc'),
   });
 
-  assert.equal(dir, path.join(xdgConfigHome, 'SubMiner'));
+  assert.equal(dir, path.posix.join(xdgConfigHome, 'SubMiner'));
 });
 
 test('ensureDefaultConfigBootstrap creates config dir and default jsonc only when missing', () => {
@@ -138,27 +139,27 @@ test('resolveDefaultMpvInstallPaths resolves linux, macOS, and Windows defaults'
   const xdgConfigHome = path.join(path.sep, 'tmp', 'xdg');
   assert.deepEqual(resolveDefaultMpvInstallPaths('linux', linuxHomeDir, xdgConfigHome), {
     supported: true,
-    mpvConfigDir: path.join(xdgConfigHome, 'mpv'),
-    scriptsDir: path.join(xdgConfigHome, 'mpv', 'scripts'),
-    scriptOptsDir: path.join(xdgConfigHome, 'mpv', 'script-opts'),
-    pluginEntrypointPath: path.join(xdgConfigHome, 'mpv', 'scripts', 'subminer', 'main.lua'),
-    pluginDir: path.join(xdgConfigHome, 'mpv', 'scripts', 'subminer'),
-    pluginConfigPath: path.join(xdgConfigHome, 'mpv', 'script-opts', 'subminer.conf'),
+    mpvConfigDir: path.posix.join(xdgConfigHome, 'mpv'),
+    scriptsDir: path.posix.join(xdgConfigHome, 'mpv', 'scripts'),
+    scriptOptsDir: path.posix.join(xdgConfigHome, 'mpv', 'script-opts'),
+    pluginEntrypointPath: path.posix.join(xdgConfigHome, 'mpv', 'scripts', 'subminer', 'main.lua'),
+    pluginDir: path.posix.join(xdgConfigHome, 'mpv', 'scripts', 'subminer'),
+    pluginConfigPath: path.posix.join(xdgConfigHome, 'mpv', 'script-opts', 'subminer.conf'),
   });
 
   const macHomeDir = path.join(path.sep, 'Users', 'tester');
   assert.deepEqual(resolveDefaultMpvInstallPaths('darwin', macHomeDir, undefined), {
     supported: true,
-    mpvConfigDir: path.join(macHomeDir, 'Library', 'Application Support', 'mpv'),
-    scriptsDir: path.join(macHomeDir, 'Library', 'Application Support', 'mpv', 'scripts'),
-    scriptOptsDir: path.join(
+    mpvConfigDir: path.posix.join(macHomeDir, 'Library', 'Application Support', 'mpv'),
+    scriptsDir: path.posix.join(macHomeDir, 'Library', 'Application Support', 'mpv', 'scripts'),
+    scriptOptsDir: path.posix.join(
       macHomeDir,
       'Library',
       'Application Support',
       'mpv',
       'script-opts',
     ),
-    pluginEntrypointPath: path.join(
+    pluginEntrypointPath: path.posix.join(
       macHomeDir,
       'Library',
       'Application Support',
@@ -167,7 +168,7 @@ test('resolveDefaultMpvInstallPaths resolves linux, macOS, and Windows defaults'
       'subminer',
       'main.lua',
     ),
-    pluginDir: path.join(
+    pluginDir: path.posix.join(
       macHomeDir,
       'Library',
       'Application Support',
@@ -175,7 +176,7 @@ test('resolveDefaultMpvInstallPaths resolves linux, macOS, and Windows defaults'
       'scripts',
       'subminer',
     ),
-    pluginConfigPath: path.join(
+    pluginConfigPath: path.posix.join(
       macHomeDir,
       'Library',
       'Application Support',
@@ -187,10 +188,16 @@ test('resolveDefaultMpvInstallPaths resolves linux, macOS, and Windows defaults'
 
   assert.deepEqual(resolveDefaultMpvInstallPaths('win32', 'C:\\Users\\tester', undefined), {
     supported: true,
-    mpvConfigDir: path.join('C:\\Users\\tester', 'AppData', 'Roaming', 'mpv'),
-    scriptsDir: path.join('C:\\Users\\tester', 'AppData', 'Roaming', 'mpv', 'scripts'),
-    scriptOptsDir: path.join('C:\\Users\\tester', 'AppData', 'Roaming', 'mpv', 'script-opts'),
-    pluginEntrypointPath: path.join(
+    mpvConfigDir: path.win32.join('C:\\Users\\tester', 'AppData', 'Roaming', 'mpv'),
+    scriptsDir: path.win32.join('C:\\Users\\tester', 'AppData', 'Roaming', 'mpv', 'scripts'),
+    scriptOptsDir: path.win32.join(
+      'C:\\Users\\tester',
+      'AppData',
+      'Roaming',
+      'mpv',
+      'script-opts',
+    ),
+    pluginEntrypointPath: path.win32.join(
       'C:\\Users\\tester',
       'AppData',
       'Roaming',
@@ -199,8 +206,15 @@ test('resolveDefaultMpvInstallPaths resolves linux, macOS, and Windows defaults'
       'subminer',
       'main.lua',
     ),
-    pluginDir: path.join('C:\\Users\\tester', 'AppData', 'Roaming', 'mpv', 'scripts', 'subminer'),
-    pluginConfigPath: path.join(
+    pluginDir: path.win32.join(
+      'C:\\Users\\tester',
+      'AppData',
+      'Roaming',
+      'mpv',
+      'scripts',
+      'subminer',
+    ),
+    pluginConfigPath: path.win32.join(
       'C:\\Users\\tester',
       'AppData',
       'Roaming',
diff --git a/src/shared/setup-state.ts b/src/shared/setup-state.ts
index 0a1625b4..c82cc994 100644
--- a/src/shared/setup-state.ts
+++ b/src/shared/setup-state.ts
@@ -40,6 +40,10 @@ export interface MpvInstallPaths {
   pluginConfigPath: string;
 }
 
+function getPlatformPath(platform: NodeJS.Platform): typeof path.posix | typeof path.win32 {
+  return platform === 'win32' ? path.win32 : path.posix;
+}
+
 function asObject(value: unknown): Record<string, unknown> | null {
   return value && typeof value === 'object' && !Array.isArray(value)
     ? (value as Record<string, unknown>)
@@ -223,20 +227,21 @@ export function resolveDefaultMpvInstallPaths(
   homeDir: string,
   xdgConfigHome?: string,
 ): MpvInstallPaths {
+  const platformPath = getPlatformPath(platform);
   const mpvConfigDir =
     platform === 'darwin'
-      ? path.join(homeDir, 'Library', 'Application Support', 'mpv')
+      ? platformPath.join(homeDir, 'Library', 'Application Support', 'mpv')
       : platform === 'linux'
-        ? path.join(xdgConfigHome?.trim() || path.join(homeDir, '.config'), 'mpv')
-        : path.join(homeDir, 'AppData', 'Roaming', 'mpv');
+        ? platformPath.join(xdgConfigHome?.trim() || platformPath.join(homeDir, '.config'), 'mpv')
+        : platformPath.join(homeDir, 'AppData', 'Roaming', 'mpv');
 
   return {
     supported: platform === 'linux' || platform === 'darwin' || platform === 'win32',
     mpvConfigDir,
-    scriptsDir: path.join(mpvConfigDir, 'scripts'),
-    scriptOptsDir: path.join(mpvConfigDir, 'script-opts'),
-    pluginEntrypointPath: path.join(mpvConfigDir, 'scripts', 'subminer', 'main.lua'),
-    pluginDir: path.join(mpvConfigDir, 'scripts', 'subminer'),
-    pluginConfigPath: path.join(mpvConfigDir, 'script-opts', 'subminer.conf'),
+    scriptsDir: platformPath.join(mpvConfigDir, 'scripts'),
+    scriptOptsDir: platformPath.join(mpvConfigDir, 'script-opts'),
+    pluginEntrypointPath: platformPath.join(mpvConfigDir, 'scripts', 'subminer', 'main.lua'),
+    pluginDir: platformPath.join(mpvConfigDir, 'scripts', 'subminer'),
+    pluginConfigPath: platformPath.join(mpvConfigDir, 'script-opts', 'subminer.conf'),
   };
 }