diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 16a825c..8e27189 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -7,8 +7,7 @@ on:
     branches: [main]
 
 jobs:
-  build:
-    name: Linting, typechecking and testing code
+  build-ubuntu:
     runs-on: ubuntu-latest
 
     strategy:
@@ -19,18 +18,13 @@ jobs:
     - name: Check out code
       uses: actions/checkout@v4
 
-    #- name: Setup cross compilers
-    #  run: sudo apt-get update && sudo apt-get install -y mingw-w64
-
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
 
     - name: Install Python dependencies
-      run: |
-        python -m pip install --upgrade pip
-        python -m pip install -e .[dev]
+      run: python -m pip install -e .[dev]
 
     - name: Build ops obj files and runner
       run: bash build.sh
@@ -48,11 +42,57 @@ jobs:
       uses: actions/upload-artifact@v4
       if: strategy.job-index == 0
       with:
-        name: object files
+        name: stencil-object-files
         path: src/copapy/obj/*.o
 
     - name: Upload compiled runner
       uses: actions/upload-artifact@v4
+      if: strategy.job-index == 0
       with:
-        name: runner
+        name: runner-linux
+        path: bin/*
+
+  build-windows:
+    needs: [build-ubuntu]
+    runs-on: windows-latest
+
+    strategy:
+      matrix:
+        python-version: ["3.10"]
+
+    steps:
+    - name: Check out code
+      uses: actions/checkout@v4
+
+    - uses: actions/download-artifact@v4
+      with:
+        name: stencil-object-files
+        path: src/copapy/obj
+
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v5
+      with:
+        python-version: ${{ matrix.python-version }}
+
+    - name: Install Python dependencies
+      run: python -m pip install -e .[dev]
+
+    - name: Build ops obj files and runner
+      run: |
+        mkdir bin
+        cl.exe /O2 src\coparun\runmem.c src\coparun\coparun.c src\coparun\mem_man.c /Fe:bin\coparun.exe
+
+    - name: Run tests with pytest
+      run: pytest
+
+    - name: Type checking with mypy
+      run: mypy
+
+    #- name: Lint code with flake8
+    #  run: flake8
+
+    - name: Upload compiled runner
+      uses: actions/upload-artifact@v4
+      with:
+        name: runner-win
         path: bin/*
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index 2ac0c77..72f2aaf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,7 +10,7 @@ __pycache__
 .pytest_cache
 /tests/autogenerated_*.py
 *test*.o
-test.copapy
+/bin/*
 token.txt
 /src/copapy/obj/*.o
 runmem2
diff --git a/build.sh b/build.sh
index 1034d3d..cf96fac 100644
--- a/build.sh
+++ b/build.sh
@@ -5,11 +5,11 @@ python src/copapy/generate_stencils.py
 SRC=src/copapy/stencils.c
 DEST=src/copapy/obj
 mkdir -p $DEST
-gcc -c $SRC -o $DEST/stencils_x86_64.o
+gcc -c $SRC -O0 -o $DEST/stencils_x86_64_O0.o
 gcc -c $SRC -O1 -o $DEST/stencils_x86_64_O1.o
 gcc -c $SRC -O2 -o $DEST/stencils_x86_64_O2.o
 gcc -c $SRC -O3 -o $DEST/stencils_x86_64_O3.o
 
 mkdir bin -p
-gcc -Wall -Wextra -Wconversion -Wsign-conversion -Wshadow -Wstrict-overflow -Werror -g src/coparun/runmem.c src/coparun/coparun.c src/coparun/mem_man.c -o bin/coparun
+gcc -Wall -Wextra -Wconversion -Wsign-conversion -Wshadow -Wstrict-overflow -Werror -g -O3 src/coparun/runmem.c src/coparun/coparun.c src/coparun/mem_man.c -o bin/coparun
 #x86_64-w64-mingw32-gcc -Wall -Wextra -Wconversion -Wsign-conversion -Wshadow -Wstrict-overflow -Werror src/runner/runmem2.c -Wall -O3 -o bin/runmem2.exe
diff --git a/test.sh b/test.sh
index ad65c35..29b7fb2 100644
--- a/test.sh
+++ b/test.sh
@@ -4,4 +4,4 @@ echo "Compile..."
 python tests/test_compile.py
 echo "Run..."
 echo "-----------------------------------"
-./bin/coparun test.copapy
\ No newline at end of file
+bin/coparun bin/test.copapy
\ No newline at end of file
diff --git a/tests/test_compile.py b/tests/test_compile.py
index f8582fa..7637ee9 100644
--- a/tests/test_compile.py
+++ b/tests/test_compile.py
@@ -35,8 +35,6 @@ def test_example():
 
 def test_compile():
 
-    print(run_command(['bash', 'build.sh']))
-
     #c1 = const(1.11)
     #c2 = const(2.22)
 
@@ -70,9 +68,9 @@ def test_compile():
     print('* Data to runner:')
     il.print()
 
-    il.to_file('test.copapy')
+    il.to_file('bin/test.copapy')
 
-    result = run_command(['./bin/coparun', 'test.copapy'])
+    result = run_command(['bin/coparun', 'bin/test.copapy'])
     print('* Output from runner:')
     print(result)