To uninstall Mixere, you need to do two things:

  1. Delete Mixere's program files from whatever folder you copied them to.
  2. Delete Mixere's registry entries.

To delete the registry entries, run the uninstaller, MixereUninstall.exe, which is included in the binary distribution. If you prefer to do it yourself using regedit, the key you want to delete is "HKEY_CURRENT_USER\Software\Anal Software".