How do I convert an AAC file to MP3 on my Windows 11 computer?

Try itunes, although iTunes is no longer mainstream, it is still a relatively simple audio management tool that supports converting AAC to MP3 format:

1. Open iTunes and import the AAC file you want to convert.
2. Select "Preferences" under the "Edit" menu, then select "Import Settings", select the MP3 format and the bit rate you want (for example: 192kbps or 256kbps).
3. Select the AAC file you want to convert, right-click and click "Create MP3 Version", and iTunes will automatically generate the MP3 format file.

This is a very simple way, provided that you have iTunes and it works properly.