diff --git a/scripts/test.sh b/scripts/test.sh
index 9c32b1f9..8b0dd7af 100755
--- a/scripts/test.sh
+++ b/scripts/test.sh
@@ -3,9 +3,21 @@ set -euo pipefail
 
 ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 VENV_DIR="$ROOT/.venv"
-VENV_PY="$VENV_DIR/bin/python"
 REQ_FILE="$ROOT/requirements-dev.txt"
 
+resolve_venv_python() {
+  local candidate
+  for candidate in "$VENV_DIR/bin/python" "$VENV_DIR/Scripts/python.exe"; do
+    if [[ -x "$candidate" ]]; then
+      printf '%s\n' "$candidate"
+      return 0
+    fi
+  done
+  return 1
+}
+
+VENV_PY="$(resolve_venv_python || true)"
+
 is_supported_python() {
   "$1" - <<'PY' >/dev/null 2>&1
 import sys
@@ -115,9 +127,10 @@ create_or_rebuild_venv() {
     venv_guidance "$base_py"
     return 2
   fi
+  VENV_PY="$(resolve_venv_python || true)"
   if [[ ! -x "$VENV_PY" ]]; then
     rm -rf "$VENV_DIR"
-    echo "$VENV_DIR was created but does not contain bin/python." >&2
+    echo "$VENV_DIR was created but does not contain bin/python or Scripts/python.exe." >&2
     venv_guidance "$base_py"
     return 2
   fi
@@ -157,6 +170,7 @@ select_python() {
     desired_major_minor=""
   fi
 
+  VENV_PY="$(resolve_venv_python || true)"
   if [[ -x "$VENV_PY" ]]; then
     if is_supported_python "$VENV_PY"; then
       current_major_minor="$(python_major_minor "$VENV_PY")"
@@ -182,7 +196,7 @@ select_python() {
   fi
 
   if [[ -e "$VENV_DIR" && ! -x "$VENV_PY" ]]; then
-    echo "$VENV_DIR exists but does not contain bin/python; rebuilding." >&2
+    echo "$VENV_DIR exists but does not contain bin/python or Scripts/python.exe; rebuilding." >&2
     create_or_rebuild_venv "$base_py" rebuild || return $?
     printf '%s\n' "$VENV_PY"
     return 0
diff --git a/tests/test_ci_hygiene.py b/tests/test_ci_hygiene.py
index 88130537..110d26f9 100644
--- a/tests/test_ci_hygiene.py
+++ b/tests/test_ci_hygiene.py
@@ -1,9 +1,17 @@
 """Small hygiene regression checks for CI and frontend console noise."""
 
+import os
+import shutil
+import stat
+import subprocess
+import textwrap
 from pathlib import Path
 
 ROOT = Path(__file__).resolve().parents[1]
 
+def _make_executable(path):
+    path.chmod(path.stat().st_mode | stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH)
+
 
 def test_github_actions_quotes_pyyaml_version_specifier():
     """Unquoted `pyyaml>=6.0` is parsed by the shell as stdout redirection."""
@@ -29,6 +37,8 @@ def test_local_test_runner_uses_supported_venv_before_pytest_collection():
     assert "python3.13 python3.12 python3.11 python3" in runner
     assert "requirements-dev.txt" in runner
     assert 'HERMES_WEBUI_TEST_PYTHON' in runner
+    assert "resolve_venv_python()" in runner
+    assert '"$VENV_DIR/bin/python" "$VENV_DIR/Scripts/python.exe"' in runner
     assert '[[ -x "$candidate" ]] && printf' in runner
     assert "exec \"$PYTHON_BIN\" -m pytest" in runner
     # Destructive-fs guard: never create/clear a virtualenv through a symlinked .venv
@@ -46,16 +56,152 @@ def test_local_test_runner_bootstrap_handles_broken_venvs_safely():
     assert "has_pip()" in runner
     assert 'if ! "$base_py" -m venv "${venv_args[@]}"; then' in create_body
     assert 'rm -rf "$VENV_DIR"' in create_body
-    assert '[[ ! -x "$VENV_PY" ]]' in create_body
+    assert 'VENV_PY="$(resolve_venv_python || true)"' in create_body
+    assert 'does not contain bin/python or Scripts/python.exe' in create_body
     assert 'if ! has_pip "$VENV_PY"; then' in create_body
     assert 'venv_guidance "$base_py"' in create_body
     assert 'printf \'%s\\n\' "$requested_path"' not in select_body
     assert 'base_py="$requested_path"' in select_body
     assert 'desired_major_minor="$(python_major_minor "$base_py")"' in select_body
+    assert 'VENV_PY="$(resolve_venv_python || true)"' in select_body
     assert 'if has_pip "$VENV_PY"; then' in select_body
+    assert 'does not contain bin/python or Scripts/python.exe; rebuilding.' in select_body
     assert 'create_or_rebuild_venv "$base_py" rebuild' in select_body
 
 
+def test_local_test_runner_accepts_windows_layout_venv_from_base_python(tmp_path):
+    repo = tmp_path / "repo"
+    scripts_dir = repo / "scripts"
+    scripts_dir.mkdir(parents=True)
+    shutil.copy2(ROOT / "scripts" / "test.sh", scripts_dir / "test.sh")
+    _make_executable(scripts_dir / "test.sh")
+    (repo / "requirements-dev.txt").write_text("", encoding="utf-8")
+
+    fake_venv_python_source = repo / "fake-venv-python-source"
+    fake_venv_python_source.write_text(textwrap.dedent("""\
+        #!/usr/bin/env bash
+        set -euo pipefail
+        if [[ "${1:-}" == "-" ]]; then
+          program="$(cat)"
+          if [[ "$program" == *"sys.version_info[:3]"* ]]; then
+            echo "3.11.15"
+          elif [[ "$program" == *"sys.version_info[:2]"* ]]; then
+            echo "3.11"
+          fi
+          exit 0
+        fi
+        if [[ "${1:-}" == "-m" && "${2:-}" == "pip" && "${3:-}" == "--version" ]]; then
+          echo "pip 24.0"
+          exit 0
+        fi
+        if [[ "${1:-}" == "-m" && "${2:-}" == "pytest" ]]; then
+          printf '%s\\n' "$0" > "$PYTEST_PROOF_FILE"
+          printf '%s\\n' "$@" >> "$PYTEST_PROOF_FILE"
+          exit 0
+        fi
+        exit 99
+        """), encoding="utf-8")
+    _make_executable(fake_venv_python_source)
+
+    fake_base_python = repo / "fake-python"
+    fake_base_python.write_text(textwrap.dedent("""\
+        #!/usr/bin/env bash
+        set -euo pipefail
+        if [[ "${1:-}" == "-" ]]; then
+          program="$(cat)"
+          if [[ "$program" == *"sys.version_info[:3]"* ]]; then
+            echo "3.11.15"
+          elif [[ "$program" == *"sys.version_info[:2]"* ]]; then
+            echo "3.11"
+          fi
+          exit 0
+        fi
+        if [[ "${1:-}" == "-m" && "${2:-}" == "venv" ]]; then
+          target="${@: -1}"
+          mkdir -p "$target/Scripts"
+          cp "$FAKE_VENV_PY_SOURCE" "$target/Scripts/python.exe"
+          chmod +x "$target/Scripts/python.exe"
+          exit 0
+        fi
+        exit 99
+        """), encoding="utf-8")
+    _make_executable(fake_base_python)
+
+    proof = repo / "pytest-proof.txt"
+    env = os.environ.copy()
+    env["HERMES_WEBUI_TEST_PYTHON"] = "./fake-python"
+    env["FAKE_VENV_PY_SOURCE"] = "./fake-venv-python-source"
+    env["PYTEST_PROOF_FILE"] = str(proof)
+
+    result = subprocess.run(
+        ["bash", "scripts/test.sh", "tests/example_test.py", "-v", "--timeout=60"],
+        cwd=repo,
+        env=env,
+        text=True,
+        capture_output=True,
+        timeout=20,
+        check=False,
+    )
+
+    assert result.returncode == 0, result.stderr
+    assert (repo / ".venv" / "Scripts" / "python.exe").exists()
+    proof_lines = proof.read_text(encoding="utf-8").splitlines()
+    assert proof_lines[0].replace("\\", "/").endswith("/.venv/Scripts/python.exe")
+    assert proof_lines[1:] == ["-m", "pytest", "tests/example_test.py", "-v", "--timeout=60"]
+
+def test_local_test_runner_rejects_venv_without_accepted_python_path(tmp_path):
+    repo = tmp_path / "repo"
+    scripts_dir = repo / "scripts"
+    scripts_dir.mkdir(parents=True)
+    shutil.copy2(ROOT / "scripts" / "test.sh", scripts_dir / "test.sh")
+    _make_executable(scripts_dir / "test.sh")
+    (repo / "requirements-dev.txt").write_text("", encoding="utf-8")
+    (repo / ".venv").mkdir()
+    (repo / ".venv" / "pyvenv.cfg").write_text("home = fake\n", encoding="utf-8")
+
+    fake_base_python = repo / "fake-python"
+    fake_base_python.write_text(textwrap.dedent("""\
+        #!/usr/bin/env bash
+        set -euo pipefail
+        if [[ "${1:-}" == "-" ]]; then
+          program="$(cat)"
+          if [[ "$program" == *"sys.version_info[:3]"* ]]; then
+            echo "3.11.15"
+          elif [[ "$program" == *"sys.version_info[:2]"* ]]; then
+            echo "3.11"
+          fi
+          exit 0
+        fi
+        if [[ "${1:-}" == "-m" && "${2:-}" == "venv" ]]; then
+          target="${@: -1}"
+          mkdir -p "$target"
+          touch "$target/pyvenv.cfg"
+          exit 0
+        fi
+        exit 99
+        """), encoding="utf-8")
+    _make_executable(fake_base_python)
+
+    proof = repo / "pytest-proof.txt"
+    env = os.environ.copy()
+    env["HERMES_WEBUI_TEST_PYTHON"] = "./fake-python"
+    env["PYTEST_PROOF_FILE"] = str(proof)
+
+    result = subprocess.run(
+        ["bash", "scripts/test.sh", "tests/example_test.py", "-v", "--timeout=60"],
+        cwd=repo,
+        env=env,
+        text=True,
+        capture_output=True,
+        timeout=20,
+        check=False,
+    )
+
+    assert result.returncode == 2
+    assert "does not contain bin/python or Scripts/python.exe" in result.stderr
+    assert not proof.exists()
+    assert not (repo / ".venv").exists()
+
 def test_live_model_success_log_is_debug_not_default_console_log():
     ui = (ROOT / "static" / "ui.js").read_text(encoding="utf-8")