# RuntimeError: add_reader() is not supported on Windows

- **ID:** `python/asyncio-loop-add-reader`
- **Domain:** python
- **Category:** system_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

Using asyncio.add_reader() or add_writer() on Windows, which uses ProactorEventLoop by default.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.7 | active | — | — |
| 3.8 | active | — | — |

## Workarounds

1. **** (90% success)
   ```
   reader, writer = await asyncio.open_connection(host, port)
   ```
2. **** (95% success)
   ```
   asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())
   ```

## Dead Ends

- **** — Same issue; the loop type is still Proactor. (90% fail)
- **** — Works but may have other limitations on Windows. (30% fail)