diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c45ceaa63..f70432267 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -27,15 +27,6 @@ jobs:
 
     steps:
 
-      # Get vcpython27 on Windows + Python 2.7, to build netifaces
-      # extension.  See https://chocolatey.org/packages/vcpython27 and
-      # https://github.com/crazy-max/ghaction-chocolatey
-      - name: Install MSVC 9.0 for Python 2.7 [Windows]
-        if: matrix.os == 'windows-latest' && matrix.python-version == '2.7'
-        uses: crazy-max/ghaction-chocolatey@v1
-        with:
-          args: install vcpython27
-
       # See https://github.com/actions/checkout. A fetch-depth of 0
       # fetches all tags and branches.
       - name: Check out Tahoe-LAFS sources
@@ -44,10 +35,35 @@ jobs:
           fetch-depth: 0
 
       - name: Set up Python ${{ matrix.python-version }}
+        if: ${{ matrix.os != 'windows-latest' }}
         uses: actions/setup-python@v1
         with:
           python-version: ${{ matrix.python-version }}
 
+      # See note below about need for using 32-bit Python 2.7 on
+      # Windows.  The extra handling here for Python 3.6 on Windows is
+      # because I could not figure out the right GitHub Actions
+      # expression to do this in a better way.
+      - name: Set up Python ${{ matrix.python-version }} [Windows x64]
+        if: ${{ ( matrix.os == 'windows-latest' ) && ( matrix.python-version == '3.6' ) }}
+        uses: actions/setup-python@v1
+        with:
+          python-version: ${{ matrix.python-version }}
+          architecture: 'x64'
+
+      # We use netifaces, which does not ship a 64-bit wheel for the
+      # Python 2.7 + Windows combination, but it ships a 32-bit wheel.
+      # Since MS has removed vcpython27 compiler downloads from their
+      # usual download site, building a netifaces wheel locally is not
+      # an option anymore.  So let us just test with 32-bit Python on
+      # Windows.
+      - name: Set up Python ${{ matrix.python-version }} [Windows x86]
+        if: ${{ ( matrix.os == 'windows-latest' ) && ( matrix.python-version == '2.7' ) }}
+        uses: actions/setup-python@v1
+        with:
+          python-version: ${{ matrix.python-version }}
+          architecture: 'x86'
+
       # To use pip caching with GitHub Actions in an OS-independent
       # manner, we need `pip cache dir` command, which became
       # available since pip v20.1+.  At the time of writing this,
@@ -164,15 +180,6 @@ jobs:
 
     steps:
 
-      # Get vcpython27 for Windows + Python 2.7, to build netifaces
-      # extension.  See https://chocolatey.org/packages/vcpython27 and
-      # https://github.com/crazy-max/ghaction-chocolatey
-      - name: Install MSVC 9.0 for Python 2.7 [Windows]
-        if: matrix.os == 'windows-latest' && matrix.python-version == '2.7'
-        uses: crazy-max/ghaction-chocolatey@v1
-        with:
-          args: install vcpython27
-
       - name: Install Tor [Ubuntu]
         if: matrix.os == 'ubuntu-latest'
         run: sudo apt install tor
@@ -193,10 +200,19 @@ jobs:
           fetch-depth: 0
 
       - name: Set up Python ${{ matrix.python-version }}
+        if: ${{ matrix.os != 'windows-latest' }}
         uses: actions/setup-python@v1
         with:
           python-version: ${{ matrix.python-version }}
 
+      # See this step under coverage job.
+      - name: Set up Python ${{ matrix.python-version }} [Windows x86]
+        if: ${{ matrix.os == 'windows-latest' }}
+        uses: actions/setup-python@v1
+        with:
+          python-version: ${{ matrix.python-version }}
+          architecture: 'x86'
+
       - name: Get pip cache directory
         id: pip-cache
         run: |
@@ -242,25 +258,25 @@ jobs:
 
     steps:
 
-      # Get vcpython27 for Windows + Python 2.7, to build netifaces
-      # extension.  See https://chocolatey.org/packages/vcpython27 and
-      # https://github.com/crazy-max/ghaction-chocolatey
-      - name: Install MSVC 9.0 for Python 2.7 [Windows]
-        if: matrix.os == 'windows-latest' && matrix.python-version == '2.7'
-        uses: crazy-max/ghaction-chocolatey@v1
-        with:
-          args: install vcpython27
-
       - name: Check out Tahoe-LAFS sources
         uses: actions/checkout@v2
         with:
           fetch-depth: 0
 
       - name: Set up Python ${{ matrix.python-version }}
+        if: ${{ matrix.os != 'windows-latest' }}
         uses: actions/setup-python@v1
         with:
           python-version: ${{ matrix.python-version }}
 
+      # See this step under coverage job.
+      - name: Set up Python ${{ matrix.python-version }} [Windows x86]
+        if: ${{ matrix.os == 'windows-latest' }}
+        uses: actions/setup-python@v1
+        with:
+          python-version: ${{ matrix.python-version }}
+          architecture: 'x86'
+
       - name: Get pip cache directory
         id: pip-cache
         run: |
diff --git a/newsfragments/3681.installation b/newsfragments/3681.installation
new file mode 100644
index 000000000..a697e6c60
--- /dev/null
+++ b/newsfragments/3681.installation
@@ -0,0 +1,3 @@
+Tahoe-LAFS CI now runs tests only on 32-bit Windows. Microsoft has
+removed vcpython27 compiler downloads from their site, and Tahoe-LAFS
+needs vcpython27 to build and install netifaces on 64-bit Windows.