@@ -0,0 +1,111 @@
+name: Build Windows wheels
+
+# Builds the Windows wheels kept in whl_files/ for the Python versions and
+# machines PyPI carries no wheel for, so a Windows install needs no compiler.
+# Each package is built from its PyPI sdist, checked against the pinned
+# sha256, then installed into a clean venv and exercised before upload.
+# Download the artifacts and commit the wheels by hand, with a requirements.txt
+# line for each.
+#
+# Gaps covered, measured against PyPI on 2026-10-19:
+#   x64 3.15: no cp315 wheels for pyliblzfse, astc-decomp-faster, pyahocorasick.
+#   ARM64 3.11 to 3.15: none of those three publishes win_arm64 wheels.
+# numpy 1.26.4 has no win_arm64 wheel either, and MSVC 19.51 stops on it with
+# internal compiler errors, so requirements.txt gives Windows ARM64 numpy 2.
+# setup-python offers Windows ARM64 builds of Python from 3.11 only.
+
+on:
+  # A change to this file rebuilds and checks every wheel.
+  pull_request:
+    paths:
+      - '.github/workflows/build_windows_wheels.yml'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    name: build ${{ matrix.package.name }} ${{ matrix.target.arch }} ${{ matrix.target.python }}
+    runs-on: ${{ matrix.target.runner }}
+    strategy:
+      fail-fast: false
+      matrix:
+        target:
+          - { runner: windows-latest, arch: x64, python: '3.15' }
+          - { runner: windows-11-arm, arch: arm64, python: '3.11' }
+          - { runner: windows-11-arm, arch: arm64, python: '3.12' }
+          - { runner: windows-11-arm, arch: arm64, python: '3.13' }
+          - { runner: windows-11-arm, arch: arm64, python: '3.14' }
+          - { runner: windows-11-arm, arch: arm64, python: '3.15' }
+        package:
+          - name: pyliblzfse
+            version: 0.4.1
+            sdist: https://files.pythonhosted.org/packages/2c/ba/a4bc465d36f6aafbff89da1bf67bcc6a97475b1d2300a74a778dcb293cef/pyliblzfse-0.4.1.tar.gz
+            sha256: bb0b899b3830c02fdf3dbde48ea59611833f366fef836e5c32cf8145134b7d3d
+            check: |
+              import liblzfse
+              data = bytes(range(256)) * 64
+              assert liblzfse.decompress(liblzfse.compress(data)) == data
+          - name: astc-decomp-faster
+            version: 1.1.5
+            sdist: https://files.pythonhosted.org/packages/46/0c/9175a74d7dfb5743b027b97dc15127802d882cb1154b779fe857801ca325/astc_decomp_faster-1.1.5.tar.gz
+            sha256: c84865c97231996a9a4f12c9f4d676633808afe62f4df230dfd740ee7d3054b4
+            needs: pillow
+            check: |
+              import astc_decomp_faster  # registers Pillow's "astc" decoder
+              from PIL import Image
+              # A void-extent block: one constant colour for the whole 4x4 block.
+              block = bytes([0xFC, 0xFD, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+                             0x00, 0xFF, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF])
+              image = Image.frombytes('RGBA', (4, 4), block, 'astc', (4, 4, False))
+              assert image.getpixel((0, 0)) == (255, 0, 0, 255), image.getpixel((0, 0))
+          - name: pyahocorasick
+            version: 2.3.1
+            sdist: https://files.pythonhosted.org/packages/b0/3c/dc9e31a0f004eabe2ef5d31456766555a02e2af29e159daa31266934af79/pyahocorasick-2.3.1.tar.gz
+            sha256: 9d0f6bb522237ed7f111ed59c9e8baea7d1e75813587b6773babd43bda35db9f
+            check: |
+              import ahocorasick
+              automaton = ahocorasick.Automaton()
+              for word in ('he', 'she', 'hers'):
+                  automaton.add_word(word, word)
+              automaton.make_automaton()
+              assert sorted(found for _, found in automaton.iter('ushers')) == ['he', 'hers', 'she']
+
+    steps:
+      - uses: actions/setup-python@v7
+        with:
+          python-version: ${{ matrix.target.python }}
+          architecture: ${{ matrix.target.arch }}
+
+      - name: Download and verify the sdist
+        shell: bash
+        run: |
+          curl -sSfL -o sdist.tar.gz "${{ matrix.package.sdist }}"
+          echo "${{ matrix.package.sha256 }}  sdist.tar.gz" | sha256sum -c -
+
+      - name: Build the wheel
+        shell: bash
+        run: python -m pip wheel --no-deps --wheel-dir dist sdist.tar.gz
+
+      - name: Install into a clean venv and exercise it
+        shell: bash
+        env:
+          CHECK: ${{ matrix.package.check }}
+        run: |
+          python -m venv check
+          check/Scripts/python -m pip install --quiet --no-index dist/*.whl
+          if [ -n "${{ matrix.package.needs }}" ]; then
+            check/Scripts/python -m pip install --quiet --only-binary=:all: ${{ matrix.package.needs }}
+          fi
+          printf '%s\n' "$CHECK" > check.py
+          check/Scripts/python check.py
+          check/Scripts/python -c "import platform, sys; print(sys.version, platform.machine())"
+          sha256sum dist/*.whl
+          python -m zipfile -l dist/*.whl
+
+      - uses: actions/upload-artifact@v7
+        with:
+          name: ${{ matrix.package.name }}-${{ matrix.package.version }}-py${{ matrix.target.python }}-${{ matrix.target.arch }}
+          path: dist/*.whl
+          if-no-files-found: error
@@ -31,10 +31,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        # The versions README.md tells users to run, plus 3.15 ahead of it.
-        # README stays at 3.14 until 3.15 installs on Windows x64 without a
-        # compiler: pyahocorasick and astc-decomp-faster publish no cp315
-        # wheels yet, and whl_files has no cp315 pyliblzfse wheel.
+        # The versions README.md tells users to run
         python-version: ['3.10', '3.11', '3.12', '3.13', '3.14', '3.15']
 
     steps:
@@ -58,3 +55,51 @@ jobs:
 
       - name: Run admin compatibility tests
         run: python -m unittest discover -s admin/test/scripts -p 'test_*.py'
+
+  install:
+    # README promises these versions. On Windows, x64 and ARM64, they must
+    # install with no compiler: only the pure-Python packages that publish no
+    # wheels may build from source, so a compiled package without a wheel on
+    # PyPI or in whl_files fails here. Windows ARM64 Python starts at 3.11 in
+    # setup-python. macOS installs as users do; pyliblzfse has no macOS wheels,
+    # so a compiler is needed there on every version.
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [windows-latest, macos-latest]
+        python-version: ['3.10', '3.11', '3.12', '3.13', '3.14', '3.15']
+        include:
+          - { os: windows-11-arm, python-version: '3.11' }
+          - { os: windows-11-arm, python-version: '3.12' }
+          - { os: windows-11-arm, python-version: '3.13' }
+          - { os: windows-11-arm, python-version: '3.14' }
+          - { os: windows-11-arm, python-version: '3.15' }
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v7
+        with:
+          sparse-checkout: |
+            /*
+            !/admin/test/cases/data
+          sparse-checkout-cone-mode: false
+
+      - name: Set up Python
+        uses: actions/setup-python@v7
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install runtime dependencies from wheels (Windows)
+        if: runner.os == 'Windows'
+        run: |
+          python -m pip install --only-binary=:all: --no-binary=biplist,pgpy,nska-deserialize -r requirements.txt
+
+      - name: Install runtime dependencies (macOS)
+        if: runner.os == 'macOS'
+        run: |
+          python -m pip install -r requirements.txt
+
+      - name: Import the compiled dependencies
+        run: |
+          python -c "import liblzfse, astc_decomp_faster, ahocorasick, numpy, pandas, PIL, pillow_heif, Crypto, mmh3; print('ok')"
@@ -187,7 +187,7 @@ Releases are the easiest way to run iLEAPP. Use source if you are developing mod
 
 ### Requirements
 
-- Python 3.10 to 3.14
+- Python 3.10 to 3.15
 - Git
 
 ### Setup
 
@@ -1,4 +1,42 @@
+# Windows wheels kept in whl_files/, for the Python versions and machines PyPI
+# has no wheel for, so a Windows install needs no compiler. A local wheel is used
+# only when its line comes before the bare requirement of the same name, so these
+# lines stay at the top. The cp310 to cp314 win_amd64 pyliblzfse wheels predate
+# .github/workflows/build_windows_wheels.yml, which built every other wheel here.
+# The markers pin the machine as well as the OS, or pip would try a win_amd64
+# wheel on Windows ARM64.
+whl_files/pyliblzfse-0.4.1-cp310-cp310-win_amd64.whl; python_version == "3.10" and platform_system == "Windows" and platform_machine == "AMD64"
+whl_files/pyliblzfse-0.4.1-cp311-cp311-win_amd64.whl; python_version == "3.11" and platform_system == "Windows" and platform_machine == "AMD64"
+whl_files/pyliblzfse-0.4.1-cp312-cp312-win_amd64.whl; python_version == "3.12" and platform_system == "Windows" and platform_machine == "AMD64"
+whl_files/pyliblzfse-0.4.1-cp313-cp313-win_amd64.whl; python_version == "3.13" and platform_system == "Windows" and platform_machine == "AMD64"
+whl_files/pyliblzfse-0.4.1-cp314-cp314-win_amd64.whl; python_version == "3.14" and platform_system == "Windows" and platform_machine == "AMD64"
+whl_files/pyliblzfse-0.4.1-cp315-cp315-win_amd64.whl; python_version == "3.15" and platform_system == "Windows" and platform_machine == "AMD64"
+whl_files/pyliblzfse-0.4.1-cp311-cp311-win_arm64.whl; python_version == "3.11" and platform_system == "Windows" and platform_machine == "ARM64"
+whl_files/pyliblzfse-0.4.1-cp312-cp312-win_arm64.whl; python_version == "3.12" and platform_system == "Windows" and platform_machine == "ARM64"
+whl_files/pyliblzfse-0.4.1-cp313-cp313-win_arm64.whl; python_version == "3.13" and platform_system == "Windows" and platform_machine == "ARM64"
+whl_files/pyliblzfse-0.4.1-cp314-cp314-win_arm64.whl; python_version == "3.14" and platform_system == "Windows" and platform_machine == "ARM64"
+whl_files/pyliblzfse-0.4.1-cp315-cp315-win_arm64.whl; python_version == "3.15" and platform_system == "Windows" and platform_machine == "ARM64"
+whl_files/astc_decomp_faster-1.1.5-cp315-cp315-win_amd64.whl; python_version == "3.15" and platform_system == "Windows" and platform_machine == "AMD64"
+whl_files/astc_decomp_faster-1.1.5-cp311-cp311-win_arm64.whl; python_version == "3.11" and platform_system == "Windows" and platform_machine == "ARM64"
+whl_files/astc_decomp_faster-1.1.5-cp312-cp312-win_arm64.whl; python_version == "3.12" and platform_system == "Windows" and platform_machine == "ARM64"
+whl_files/astc_decomp_faster-1.1.5-cp313-cp313-win_arm64.whl; python_version == "3.13" and platform_system == "Windows" and platform_machine == "ARM64"
+whl_files/astc_decomp_faster-1.1.5-cp314-cp314-win_arm64.whl; python_version == "3.14" and platform_system == "Windows" and platform_machine == "ARM64"
+whl_files/astc_decomp_faster-1.1.5-cp315-cp315-win_arm64.whl; python_version == "3.15" and platform_system == "Windows" and platform_machine == "ARM64"
+whl_files/pyahocorasick-2.3.1-cp315-cp315-win_amd64.whl; python_version == "3.15" and platform_system == "Windows" and platform_machine == "AMD64"
+whl_files/pyahocorasick-2.3.1-cp311-cp311-win_arm64.whl; python_version == "3.11" and platform_system == "Windows" and platform_machine == "ARM64"
+whl_files/pyahocorasick-2.3.1-cp312-cp312-win_arm64.whl; python_version == "3.12" and platform_system == "Windows" and platform_machine == "ARM64"
+whl_files/pyahocorasick-2.3.1-cp313-cp313-win_arm64.whl; python_version == "3.13" and platform_system == "Windows" and platform_machine == "ARM64"
+whl_files/pyahocorasick-2.3.1-cp314-cp314-win_arm64.whl; python_version == "3.14" and platform_system == "Windows" and platform_machine == "ARM64"
+whl_files/pyahocorasick-2.3.1-cp315-cp315-win_arm64.whl; python_version == "3.15" and platform_system == "Windows" and platform_machine == "ARM64"
+
 astc_decomp_faster
+# numpy 1.26.4 has no Windows ARM64 wheel, and MSVC 19.51 fails to build it there
+# (internal compiler errors), so Windows ARM64 takes numpy 2 on every version, as
+# 3.13 and later do everywhere.
+numpy==1.26.4; python_version < "3.13" and (platform_system != "Windows" or platform_machine != "ARM64")
+numpy>=2.1; python_version >= "3.13" or (platform_system == "Windows" and platform_machine == "ARM64")
+# Compiled Unified Log prefilter. Windows ARM64 on Python 3.10 uses the SQLite fallback.
+pyahocorasick==2.3.1; platform_system != "Windows" or platform_machine != "ARM64" or python_version >= "3.11"
 pytypedstream
 bencoding
 biplist
@@ -13,8 +51,6 @@ mmh3
 mdplistlib
 nska-deserialize>=1.3.1
 nska_deserialize
-numpy==1.26.4; python_version < "3.13"
-numpy>=2.1; python_version >= "3.13"
 packaging>=24.0
 pandas
 pathlib2==2.3.5
@@ -27,17 +63,6 @@ pillow_heif
 # CVEs. 5.29.6 is the minimum that clears CVE-2022-1941/2025-4565/2026-0994.
 protobuf==5.29.6
 pycryptodome
-# Compiled Unified Log prefilter. Native Windows ARM64 uses the SQLite fallback.
-pyahocorasick==2.3.1; platform_system != "Windows" or platform_machine == "AMD64"
-
-# pyliblzfse for Windows on x64. The markers pin the machine as well as the OS:
-# these wheels are win_amd64, and on Windows-on-ARM pip would otherwise try to
-# install them and fail. ARM builds compile pyliblzfse from the sdist below.
-whl_files/pyliblzfse-0.4.1-cp310-cp310-win_amd64.whl; python_version == "3.10" and platform_system == "Windows" and platform_machine == "AMD64"
-whl_files/pyliblzfse-0.4.1-cp311-cp311-win_amd64.whl; python_version == "3.11" and platform_system == "Windows" and platform_machine == "AMD64"
-whl_files/pyliblzfse-0.4.1-cp312-cp312-win_amd64.whl; python_version == "3.12" and platform_system == "Windows" and platform_machine == "AMD64"
-whl_files/pyliblzfse-0.4.1-cp313-cp313-win_amd64.whl; python_version == "3.13" and platform_system == "Windows" and platform_machine == "AMD64"
-whl_files/pyliblzfse-0.4.1-cp314-cp314-win_amd64.whl; python_version == "3.14" and platform_system == "Windows" and platform_machine == "AMD64"
 
 pyliblzfse