vllm serve fails with ModuleNotFoundError: No module named 'vllm._C'

I am following installation guide on Windows 11 x64.

vllm serve fails

(.venv) PS D:\Experiments\fara> vllm serve "microsoft/Fara-7B" --port 5000 --dtype auto
Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "D:\Experiments\fara\.venv\Scripts\vllm.exe\__main__.py", line 2, in <module>
    from vllm.entrypoints.cli.main import main
  File "D:\Experiments\fara\.venv\Lib\site-packages\vllm\entrypoints\cli\__init__.py", line 3, in <module>
    from vllm.entrypoints.cli.benchmark.latency import BenchmarkLatencySubcommand
  File "D:\Experiments\fara\.venv\Lib\site-packages\vllm\entrypoints\cli\benchmark\latency.py", line 5, in <module>
    from vllm.benchmarks.latency import add_cli_args, main
  File "D:\Experiments\fara\.venv\Lib\site-packages\vllm\benchmarks\latency.py", line 17, in <module>
    from vllm.engine.arg_utils import EngineArgs
  File "D:\Experiments\fara\.venv\Lib\site-packages\vllm\engine\arg_utils.py", line 35, in <module>
    from vllm.attention.backends.registry import AttentionBackendEnum
  File "D:\Experiments\fara\.venv\Lib\site-packages\vllm\attention\__init__.py", line 4, in <module>
    from vllm.attention.backends.abstract import (
    ...<3 lines>...
    )
  File "D:\Experiments\fara\.venv\Lib\site-packages\vllm\attention\backends\abstract.py", line 9, in <module>
    from vllm.model_executor.layers.linear import ColumnParallelLinear
  File "D:\Experiments\fara\.venv\Lib\site-packages\vllm\model_executor\__init__.py", line 4, in <module>
    from vllm.model_executor.parameter import BasevLLMParameter, PackedvLLMParameter
  File "D:\Experiments\fara\.venv\Lib\site-packages\vllm\model_executor\parameter.py", line 11, in <module>
    from vllm.distributed import (
    ...<2 lines>...
    )
  File "D:\Experiments\fara\.venv\Lib\site-packages\vllm\distributed\__init__.py", line 4, in <module>
    from .communication_op import *
  File "D:\Experiments\fara\.venv\Lib\site-packages\vllm\distributed\communication_op.py", line 9, in <module>
    from .parallel_state import get_tp_group
  File "D:\Experiments\fara\.venv\Lib\site-packages\vllm\distributed\parallel_state.py", line 250, in <module>
    direct_register_custom_op(
    ~~~~~~~~~~~~~~~~~~~~~~~~~^
        op_name="all_reduce",
        ^^^^^^^^^^^^^^^^^^^^^
        op_func=all_reduce,
        ^^^^^^^^^^^^^^^^^^^
        fake_impl=all_reduce_fake,
        ^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "D:\Experiments\fara\.venv\Lib\site-packages\vllm\utils\torch_utils.py", line 640, in direct_register_custom_op
    from vllm.platforms import current_platform
  File "D:\Experiments\fara\.venv\Lib\site-packages\vllm\platforms\__init__.py", line 257, in __getattr__
    _current_platform = resolve_obj_by_qualname(platform_cls_qualname)()
                        ~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\Experiments\fara\.venv\Lib\site-packages\vllm\utils\import_utils.py", line 89, in resolve_obj_by_qualname
    module = importlib.import_module(module_name)
  File "C:\Users\rail\AppData\Local\Programs\Python\Python313\Lib\importlib\__init__.py", line 88, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\Experiments\fara\.venv\Lib\site-packages\vllm\platforms\cuda.py", line 16, in <module>
    import vllm._C  # noqa
    ^^^^^^^^^^^^^^
ModuleNotFoundError: No module named 'vllm._C'

Start with the installation guide and the reported vllm serve command on Windows 11 x64. Trace the import path through the listed vllm.platforms.cuda and vllm._C entry points, then verify the documented platform and installation expectations. Done means the guide or issue outcome clearly explains this invocation and its supported result.