diff --git a/components/bin/build b/components/bin/build
index 68360eac4..ef46205c7 100755
--- a/components/bin/build
+++ b/components/bin/build
@@ -61,6 +61,9 @@ process.chdir(path.dirname(json));
 const mjPath = path.relative(process.cwd(), path.resolve(__dirname, '..', '..', target));
 const mjGlobal = path.join('..', mjPath, 'components', 'global.js');
 
+/**
+ * Determine the module type
+ */
 function getType() {
   const component = config.component || 'part';
   if (component.match(/\/(svg|chtml|common)\/fonts\//)) return RegExp.$1 + '-font';
@@ -69,6 +72,13 @@ function getType() {
   return component;
 }
 
+/**
+ * Convert Windows paths to unix paths
+ */
+const normalize = process.platform === 'win32'
+      ? (file) => file.replace(/\\/g, '/')
+      : (file) => file;
+
 /**
  * Extract the configuration values
  */
@@ -100,7 +110,7 @@ let PACKAGE = [];
  */
 function processList(base, dir, list, top = true) {
   for (const item of list) {
-    const file = path.join(dir, item);
+    const file = normalize(path.join(dir, item));
     if (!EXCLUDE.has(file)) {
       const stat = fs.statSync(path.resolve(base, file));
       if (stat.isDirectory()) {
@@ -271,12 +281,12 @@ function getExtraDirectories() {
 function processGlobal() {
   console.info('  ' + COMPONENT + '.ts');
   const lines = (target === 'cjs' ? [
-    `const {combineWithMathJax} = require('${GLOBAL}')`,
-    `const {VERSION} = require('${VERSION}');`,
+    `const {combineWithMathJax} = require('${normalize(GLOBAL)}')`,
+    `const {VERSION} = require('${normalize(VERSION)}');`,
     '',
   ] : [
-    `import {combineWithMathJax} from '${GLOBAL}';`,
-    `import {VERSION} from '${VERSION}';`,
+    `import {combineWithMathJax} from '${normalize(GLOBAL)}';`,
+    `import {VERSION} from '${normalize(VERSION)}';`,
     '',
   ]);
   const [prefix, indent, postfix] = getExtraDirectories();
@@ -337,7 +347,7 @@ function processPackage(lines, space, dir) {
     if (path.dirname(PACKAGE[0]) === dir) {
       const file = PACKAGE.shift();
       const name = path.basename(file);
-      let relativefile = path.join('..', JS, dir, name).replace(/\.ts$/, '.js')
+      const relativefile = normalize(path.join('..', JS, dir, name).replace(/\.ts$/, '.js'));
       const component = 'module' + (++importCount);
       lines.push(
         target === 'cjs' ?
diff --git a/components/bin/makeAll b/components/bin/makeAll
index b661d3696..8eafa678c 100755
--- a/components/bin/makeAll
+++ b/components/bin/makeAll
@@ -124,6 +124,13 @@ function fileRegExp(name) {
   return new RegExp(name.replace(/([\\.{}[\]()?*^$])/g, '\\$1'), 'g');
 }
 
+/**
+ * Options for the execSync() function
+ */
+const execOptions = process.platform === 'win32'
+      ? { shell: `${process.env.ProgramFiles}\\Git\\bin\\bash.exe` }
+      : {};
+
 /**
  * Get the current working directory
  */
@@ -196,7 +203,7 @@ function processSubdirs(dir, action, config) {
  * Run a command on a given directory
  */
 function run(cmd, dir) {
-  return execSync(cmd + ` '${path.relative('.', dir).replace(/'/g, '\\\'')}'`);
+  return execSync(cmd + ` '${path.relative('.', dir).replace(/'/g, '\\\'')}'`, execOptions);
 }
 
 /**
diff --git a/components/bin/pack b/components/bin/pack
index ebcf8a214..4a91ab5de 100755
--- a/components/bin/pack
+++ b/components/bin/pack
@@ -25,7 +25,7 @@
 
 const fs = require('fs');
 const path = require('path');
-const {spawn, execSync} = require('child_process');
+const {spawn} = require('child_process');
 
 /**
  * The module type to use ('cjs' or 'mjs')
@@ -64,14 +64,7 @@ const rootRE = fileRegExp(path.dirname(jsPath));
 const nodeRE = /^.*\/node_modules/;
 const fontRE = new RegExp('^.*\\/(mathjax-[^\/-]*)(?:-font)?\/(build|[cm]js)');
 
-/**
- * Find the directory where npx runs (so we know where "npx webpack" will run)
- * (We use npx rather than pnpm here as it seems that pnpm doesn't
- * find the executable from a node_modules directory higher than the
- * first package.json, and extensions and fonts can have their own
- * package.json.)
- */
-const packDir = String(execSync('npx node -e "console.log(process.cwd())"'));
+const packDir = process.cwd();
 
 /**
  * @param {string} dir   The directory to pack
@@ -80,11 +73,20 @@ const packDir = String(execSync('npx node -e "console.log(process.cwd())"'));
 async function readJSON(dir) {
   return new Promise((ok, fail) => {
     const buffer = [];
-    const child = spawn('npx', [
-      'webpack', '--env', `dir=${path.relative(packDir, path.resolve(dir))}`,
-      '--env', `bundle=${bundle}`, '--json',
-      '-c', path.relative(packDir, path.join(compPath, 'webpack.config.' + target))
-    ]);
+    const child = spawn(
+      'npx',
+      [
+        'webpack',
+        '--env', `dir=${path.relative(packDir, path.resolve(dir))}`,
+        '--env', `bundle=${bundle}`,
+        '--json',
+        '-c', path.relative(packDir, path.join(compPath, 'webpack.config.' + target))
+      ],
+      {
+        cwd: packDir,
+        shell: true,
+      }
+    );
     child.stdout.on('data', (data) => buffer.push(String(data)));
     child.stderr.on('data', (data) => console.error(String(data)));
     child.on('close', (code) => {
diff --git a/components/mjs/a11y/speech/speech.js b/components/mjs/a11y/speech/speech.js
index a4c474b4d..4f6aae494 100644
--- a/components/mjs/a11y/speech/speech.js
+++ b/components/mjs/a11y/speech/speech.js
@@ -2,20 +2,20 @@ import './lib/speech.js';
 
 import {combineDefaults} from '#js/components/global.js';
 import {Package} from '#js/components/package.js';
-import {hasWindow} from '#js/util/context.js';
+import {context} from '#js/util/context.js';
 import {SpeechHandler} from '#js/a11y/speech.js';
 
 if (MathJax.loader) {
   let path = Package.resolvePath('[sre]', false);
   let maps = Package.resolvePath('[mathmaps]', false);
-  if (hasWindow) {
+  if (context.window) {
     path = new URL(path, location).href;
     maps = new URL(maps, location).href;
   } else {
     const REQUIRE = typeof require !== 'undefined' ? require : MathJax.config.loader.require;
     if (REQUIRE?.resolve) {
-      path = REQUIRE.resolve(`${path}/require.mjs`).replace(/\/[^\/]*$/, '');
-      maps = REQUIRE.resolve(`${maps}/base.json`).replace(/\/[^\/]*$/, '');
+      path = context.path(REQUIRE.resolve(`${path}/require.mjs`)).replace(/\/[^\/]*$/, '');
+      maps = context.path(REQUIRE.resolve(`${maps}/base.json`)).replace(/\/[^\/]*$/, '');
     } else {
       path = maps = '';
     }
diff --git a/components/mjs/node-main/node-main-setup.mjs b/components/mjs/node-main/node-main-setup.mjs
index f143f4233..793a66e4e 100644
--- a/components/mjs/node-main/node-main-setup.mjs
+++ b/components/mjs/node-main/node-main-setup.mjs
@@ -4,4 +4,4 @@ global.require = createRequire(import.meta.url);
 const path = require("path");
 
 if (!global.MathJax) global.MathJax = {};
-global.MathJax.__dirname =  path.dirname(new URL(import.meta.url).pathname);
+global.MathJax.__dirname = path.dirname(new URL(import.meta.url).pathname);
diff --git a/components/mjs/node-main/node-main.js b/components/mjs/node-main/node-main.js
index 13b635173..e09f18270 100644
--- a/components/mjs/node-main/node-main.js
+++ b/components/mjs/node-main/node-main.js
@@ -23,6 +23,7 @@ import '../startup/init.js';
 import {Loader, CONFIG} from '#js/components/loader.js';
 import {Package} from '#js/components/package.js';
 import {combineDefaults, combineConfig} from '#js/components/global.js';
+import {context} from '#js/util/context.js';
 import '../core/core.js';
 import '../adaptors/liteDOM/liteDOM.js';
 import {source} from '../source.js';
@@ -30,7 +31,7 @@ import {source} from '../source.js';
 const MathJax = global.MathJax;
 
 const path = eval('require("path")');   // get path from node, not webpack
-const dir = MathJax.config.__dirname;   // set up by node-main.mjs or node-main.cjs
+const dir = context.path(MathJax.config.__dirname);   // set up by node-main.mjs or node-main.cjs
 
 /*
  * Set up the initial configuration
diff --git a/components/mjs/source-lab.js b/components/mjs/source-lab.js
index 708290300..d7455ab4a 100644
--- a/components/mjs/source-lab.js
+++ b/components/mjs/source-lab.js
@@ -15,4 +15,4 @@
  *  limitations under the License.
  */
 
-export const src = String(new URL('.', import.meta.url)).replace(/\/$/, '');
+export const dirname = String(new URL('.', import.meta.url)).replace(/\/$/, '');
diff --git a/components/mjs/source.cjs b/components/mjs/source.cjs
index db7fddf94..bd1f9dd24 100644
--- a/components/mjs/source.cjs
+++ b/components/mjs/source.cjs
@@ -15,4 +15,4 @@
  *  limitations under the License.
  */
 
-module.exports.src = __dirname;
+module.exports.dirname = __dirname;
diff --git a/components/mjs/source.d.cts b/components/mjs/source.d.cts
index 93e9f7a7c..363367412 100644
--- a/components/mjs/source.d.cts
+++ b/components/mjs/source.d.cts
@@ -1 +1 @@
-export declare const src: string;
+export declare const dirname: string;
diff --git a/components/mjs/source.js b/components/mjs/source.js
index e632cbf88..ab4e056da 100644
--- a/components/mjs/source.js
+++ b/components/mjs/source.js
@@ -15,7 +15,9 @@
  *  limitations under the License.
  */
 
-import {src} from '#source/source.cjs';
+import {dirname} from '#source/source.cjs';
+import {context} from '#js/util/context.js';
+const src = context.path(dirname);
 
 export const source = {
   'core': `${src}/core/core.js`,
diff --git a/package.json b/package.json
index ef2dece39..ce8ce4d8a 100644
--- a/package.json
+++ b/package.json
@@ -86,9 +86,9 @@
     "copy:mml3": "copy() { pnpm -s log:single 'Copying legacy code MathML3'; pnpm copyfiles -u 1 ts/input/mathml/mml3/mml3.sef.json $1; }; copy",
     "copy:pkg": "copy() { pnpm -s log:single \"Copying package.json to $1\"; pnpm copyfiles -u 2 components/bin/package.json $1; }; copy",
     "=============================================================================== log": "",
-    "log:comp": "log() { echo \\\\033[32m$1\\\\033[0m; }; log",
-    "log:header": "log() { echo '============='; echo $1; echo '============='; }; log",
-    "log:single": "log() { echo \\\\033[34m--$1\\\\033[0m; }; log",
+    "log:comp": "log() { echo \u001B[32m$1\u001B[0m; }; log",
+    "log:header": "log() { echo '\u001B[1m============='; echo $1; echo '=============\u001B[0m'; }; log",
+    "log:single": "log() { echo \u001B[94m--$1\u001B[0m; }; log",
     "=============================================================================== cjs": "",
     "cjs:build": "pnpm -s log:header 'Building cjs'; pnpm -s cjs:src:build && pnpm -s cjs:components:build",
     "cjs:bundle:clean": "pnpm clean:dir bundle-cjs",
diff --git a/testsuite/tests/util/Context-android.test.ts b/testsuite/tests/util/Context-android.test.ts
index 4b9c88db1..d95322bde 100644
--- a/testsuite/tests/util/Context-android.test.ts
+++ b/testsuite/tests/util/Context-android.test.ts
@@ -7,6 +7,8 @@ describe('context object', () => {
 
   test('context', async () => {
     let {context, hasWindow} = await import("#js/util/context.js");
+    expect(context.path('C:\\test.js')).toBe('C:\\test.js');
+    delete context.path;
     expect(context).toEqual({window: window, document: window.document, os: 'Unix'});
     expect(hasWindow).toBe(true);
   });
diff --git a/testsuite/tests/util/Context-browser.test.ts b/testsuite/tests/util/Context-browser.test.ts
index cb5d959cf..56e939fec 100644
--- a/testsuite/tests/util/Context-browser.test.ts
+++ b/testsuite/tests/util/Context-browser.test.ts
@@ -7,6 +7,8 @@ describe('context object', () => {
 
   test('context', async () => {
     let {context, hasWindow} = await import("#js/util/context.js");
+    expect(context.path('C:\\test.js')).toBe('C:\\test.js');
+    delete context.path;
     expect(context).toEqual({window: window, document: window.document, os: 'Unix'});
     expect(hasWindow).toBe(true);
   });
diff --git a/testsuite/tests/util/Context-node-unknown.test.ts b/testsuite/tests/util/Context-node-unknown.test.ts
new file mode 100644
index 000000000..094e5514f
--- /dev/null
+++ b/testsuite/tests/util/Context-node-unknown.test.ts
@@ -0,0 +1,15 @@
+import { describe, test, expect } from '@jest/globals';
+
+global.process = {...process, platform: 'test'} as any;
+
+describe('context object', () => {
+
+  test('context', async () => {
+    let {context, hasWindow} = await import("#js/util/context.js");
+    expect(context.path('C:\\test.js')).toBe('C:\\test.js');
+    delete context.path;
+    expect(context).toEqual({window: null, document: null, os: 'test'});
+    expect(hasWindow).toBe(false);
+  });
+
+});
diff --git a/testsuite/tests/util/Context-node.test.ts b/testsuite/tests/util/Context-node.test.ts
index 8df0b38fe..fc589c87a 100644
--- a/testsuite/tests/util/Context-node.test.ts
+++ b/testsuite/tests/util/Context-node.test.ts
@@ -1,10 +1,30 @@
 import { describe, test, expect } from '@jest/globals';
 import { context, hasWindow } from '#js/util/context.js';
 
+const OS = {
+  'linux': 'Unix',
+  'android': 'Unix',
+  'aix': 'Unix',
+  'freebsd': 'Unix',
+  'netbsd': 'Unix',
+  'openbsd': 'Unix',
+  'sunos': 'Unix',
+  'darwin': 'MacOS',
+  'win32': 'Windows',
+  'cygwin': 'Windows',
+  'haiku': 'unknown',
+}[process.platform] || process.platform;
+
 describe('context object', () => {
 
   test('context', () => {
-    expect(context).toEqual({window: null, document: null, os: 'unknown'});
+    if (process.platform as string === 'Windows') {
+      expect(context.path('C:\\test.js')).toBe('C:/test.js');
+    } else {
+      expect(context.path('C:\\test.js')).toBe('C:\\test.js');
+    }
+    delete context.path;
+    expect(context).toEqual({window: null, document: null, os: OS});
     expect(hasWindow).toBe(false);
   });
 
diff --git a/testsuite/tests/util/Context-unknown.test.ts b/testsuite/tests/util/Context-unknown.test.ts
new file mode 100644
index 000000000..cc7ed9f63
--- /dev/null
+++ b/testsuite/tests/util/Context-unknown.test.ts
@@ -0,0 +1,16 @@
+import { describe, test, expect } from '@jest/globals';
+
+const window = {document: {}, navigator: {userAgent: '', appVersion: ''}};
+(global as any).window = window;
+
+describe('context object', () => {
+
+  test('context', async () => {
+    let {context, hasWindow} = await import("#js/util/context.js");
+    expect(context.path('C:\\test.js')).toBe('C:\\test.js');
+    delete context.path;
+    expect(context).toEqual({window: window, document: window.document, os: 'unknown'});
+    expect(hasWindow).toBe(true);
+  });
+
+});
diff --git a/testsuite/tests/util/Context-windows.test.ts b/testsuite/tests/util/Context-windows.test.ts
new file mode 100644
index 000000000..8b8550e40
--- /dev/null
+++ b/testsuite/tests/util/Context-windows.test.ts
@@ -0,0 +1,18 @@
+import { describe, test, expect } from '@jest/globals';
+
+const window = {document: {}, navigator: {appVersion: 'Win'}};
+(global as any).window = window;
+
+describe('context object', () => {
+
+  test('context', async () => {
+    let {context, hasWindow} = await import("#js/util/context.js");
+    expect(context.path('C:\\test.js')).toBe('C:/test.js');
+    expect(context.path('/C:/test.js')).toBe('C:/test.js');
+    expect(context.path('/test.js')).toBe('/test.js');
+    delete context.path;
+    expect(context).toEqual({window: window, document: window.document, os: 'Windows'});
+    expect(hasWindow).toBe(true);
+  });
+
+});
diff --git a/ts/components/cjs/root.ts b/ts/components/cjs/root.ts
index 137c4a5a2..e22a9cc6f 100644
--- a/ts/components/cjs/root.ts
+++ b/ts/components/cjs/root.ts
@@ -25,10 +25,13 @@
  * The location of this file
  */
 declare const __dirname: string;
+declare const require: (file: string) => any;
 
 /**
  * @return {string}   The MathJax component root directory
  */
 export function mjxRoot(): string {
-  return __dirname.replace(/[cm]js\/components\/[cm]js$/, 'bundle');
+  return require('../../util/context.js')
+    .context.path(__dirname)
+    .replace(/[cm]js\/components\/[cm]js$/, 'bundle');
 }
diff --git a/ts/components/cjs/sre-root.ts b/ts/components/cjs/sre-root.ts
index bb8cff7e9..867c41493 100644
--- a/ts/components/cjs/sre-root.ts
+++ b/ts/components/cjs/sre-root.ts
@@ -25,10 +25,13 @@
  * The location of this file
  */
 declare const __dirname: string;
+declare const require: (file: string) => any;
 
 /**
- * @return {string}   The MathJax mjs SRE root directory
+ * @return {string}   The MathJax cjs SRE root directory
  */
 export function sreRoot(): string {
-  return __dirname.replace(/components\/[cm]js$/, 'a11y/sre');
+  return require('../../util/context.js')
+    .context.path(__dirname)
+    .replace(/components\/[cm]js$/, 'a11y/sre');
 }
diff --git a/ts/components/loader.ts b/ts/components/loader.ts
index 34c2e2e56..c3b476238 100644
--- a/ts/components/loader.ts
+++ b/ts/components/loader.ts
@@ -120,7 +120,7 @@ export const PathFilters: { [name: string]: PathFilterFunction } = {
    */
   normalize: (data) => {
     const name = data.name;
-    if (!name.match(/^(?:[a-z]+:\/)?\/|[a-z]:\\|\[/i)) {
+    if (!name.match(/^(?:[a-z]+:\/)?\/|[a-z]:[/\\]|\[/i)) {
       data.name = '[mathjax]/' + name.replace(/^\.\//, '');
     }
     return true;
diff --git a/ts/components/mjs/root.ts b/ts/components/mjs/root.ts
index d8e328158..9fae578fa 100644
--- a/ts/components/mjs/root.ts
+++ b/ts/components/mjs/root.ts
@@ -21,12 +21,13 @@
  * @author dpvc@mathjax.org (Davide Cervone)
  */
 
+import { context } from '../../util/context.js';
+
 /**
  * @returns {string}   The MathJax component root directory
  */
 export function mjxRoot(): string {
-  return new URL(import.meta.url).pathname.replace(
-    /[cm]js\/components\/[cm]js\/root.js$/,
-    'bundle'
-  );
+  return context
+    .path(new URL(import.meta.url).pathname)
+    .replace(/[cm]js\/components\/[cm]js\/root.js$/, 'bundle');
 }
diff --git a/ts/components/mjs/sre-root.ts b/ts/components/mjs/sre-root.ts
index 99c44f78f..103bdf2a9 100644
--- a/ts/components/mjs/sre-root.ts
+++ b/ts/components/mjs/sre-root.ts
@@ -21,12 +21,13 @@
  * @author dpvc@mathjax.org (Davide Cervone)
  */
 
+import { context } from '../../util/context.js';
+
 /**
  * @returns {string}   The MathJax mjs SRE root directory
  */
 export function sreRoot(): string {
-  return new URL(import.meta.url).pathname.replace(
-    /components\/[cm]js\/sre-root.js$/,
-    'a11y/sre'
-  );
+  return context
+    .path(new URL(import.meta.url).pathname)
+    .replace(/components\/[cm]js\/sre-root.js$/, 'a11y/sre');
 }
diff --git a/ts/util/asyncLoad/node-import.cjs b/ts/util/asyncLoad/node-import.cjs
index 6759ea124..b5ed1d464 100644
--- a/ts/util/asyncLoad/node-import.cjs
+++ b/ts/util/asyncLoad/node-import.cjs
@@ -23,9 +23,9 @@
 
 const { mathjax } = require('../../mathjax.js');
 const path = require('path');
-const { src } = require('#source/source.cjs');
+const { dirname } = require('#source/source.cjs');
 
-let root = path.resolve(src, '..', '..', 'cjs');
+let root = path.resolve(dirname, '..', '..', 'cjs');
 
 if (!mathjax.asyncLoad) {
   mathjax.asyncLoad = async (name) => {
diff --git a/ts/util/asyncLoad/node.ts b/ts/util/asyncLoad/node.ts
index 5189a7e11..5ba06e0c7 100644
--- a/ts/util/asyncLoad/node.ts
+++ b/ts/util/asyncLoad/node.ts
@@ -23,11 +23,11 @@
 
 import { mathjax } from '../../mathjax.js';
 import * as path from 'path';
-import { src } from '#source/source.cjs';
+import { dirname } from '#source/source.cjs';
 
 declare const require: (name: string) => any;
 
-let root = path.resolve(src, '..', '..', 'cjs');
+let root = path.resolve(dirname, '..', '..', 'cjs');
 
 if (!mathjax.asyncLoad && typeof require !== 'undefined') {
   mathjax.asyncLoad = (name: string) => {
diff --git a/ts/util/context.ts b/ts/util/context.ts
index 568a7c6fa..4f5b216b3 100644
--- a/ts/util/context.ts
+++ b/ts/util/context.ts
@@ -21,6 +21,8 @@
  * @author dpvc@mathjax.org (Davide Cervone)
  */
 
+declare const process: { platform: string };
+
 /**
  * True if there is a window object
  */
@@ -49,7 +51,30 @@ export const context = {
       if (window.navigator.userAgent.includes('Android')) {
         return 'Unix';
       }
+    } else if (typeof process !== 'undefined') {
+      return (
+        {
+          linux: 'Unix',
+          android: 'Unix',
+          aix: 'Unix',
+          freebsd: 'Unix',
+          netbsd: 'Unix',
+          openbsd: 'Unix',
+          sunos: 'Unix',
+          darwin: 'MacOS',
+          win32: 'Windows',
+          cygwin: 'Windows',
+        }[process.platform] || process.platform
+      );
     }
     return 'unknown';
   })(),
+  path: (file: string) => file,
 };
+
+if (context.os === 'Windows') {
+  context.path = (file: string) =>
+    file.match(/^[/\\]?[a-zA-Z]:[/\\]/)
+      ? file.replace(/\\/g, '/').replace(/^\//, '')
+      : file;
+}