When you delete a user account from Windows, you only delete the related credentials.
All files related to the account are left untouched.
You can remove them by the following steps:
- press <windows_key> + R
- type ‘sysdm.cpl‘
- click on ‘Advanced‘ tab
- press User Profiles ‘Settings‘ button.
- select any Unknown entries and press ‘Delete‘ button.
This can free several disk MBs.