无法在Anaconda Prompt启动Jupyter Notebook（报错：async）求助

Hey there, sorry to hear you're stuck with this frustrating issue—nothing's more annoying than tools you rely on suddenly breaking, even after a full reinstall. Let's walk through some targeted fixes that often resolve these launch problems:

• Check your system environment variables
  Sometimes a reinstall fails to properly update your PATH variable, which Anaconda and Jupyter depend on to locate their executable files. Open Windows System Properties → Advanced → Environment Variables, and verify these paths are listed in your User PATH (replace [YourUsername] with your actual Windows username):

  • C:\Users\[YourUsername]\anaconda3\Scripts
  • C:\Users\[YourUsername]\anaconda3\Library\bin
    If they're missing, add them, restart your computer, and try launching Jupyter again.

• Clear corrupted conda caches
  Leftover cache files from previous installs might be causing hidden conflicts. Open Anaconda Prompt (even if it launches partially) and run:

  conda clean --all
  

  Confirm the cleanup when prompted, then close and reopen the Prompt before trying jupyter notebook again.

• Test with a fresh conda environment
  Your base environment could have lingering corruption that a reinstall didn't fix. Create a brand-new environment dedicated to Jupyter:

  conda create -n fresh_jupyter python=3.10 jupyter notebook
  conda activate fresh_jupyter
  jupyter notebook
  

  If Jupyter launches successfully here, the issue was isolated to your base environment—you can either migrate your work to this new env or dig deeper into fixing the base.

• Kill stuck background processes
  Leftover Anaconda/Python/Jupyter processes can block new launches. Open Task Manager, go to the Details tab, and end any processes named python.exe, jupyter.exe, or anaconda-navigator.exe. Then try launching your tools again.

• Use the Anaconda Repair tool
  Instead of reinstalling from scratch, try the built-in repair option. Find the Anaconda installer you used (download it again if needed), run it, and select the Repair option when prompted. This fixes corrupted files, registry entries, and config issues more precisely than a full reinstall.

If none of these steps work, sharing the exact error message you see (copy-paste the text from the Prompt or pop-up) would help narrow down the problem even further.

内容的提问来源于stack exchange，提问作者Sun Jieming