This information is for Version 2.0 of Cardbox for Windows.
We recommend that you upgrade to Cardbox 3.

Rebuilding a format file

You may want to do this

  • to reclaim space after deleting many very large formats.
  • to restructure the format file if it is approaching the 8MB limit.
  • to repair a corrupted format file.
You need version 2.0 of Cardbox for Windows.


In these instructions, we assume that your database is called "mybase.FIL".


  1. Make sure that no-one else is using this database.
  2. If the database was upgraded from Cardbox-Plus, and Cardbox-Plus users are still using it, then a file mybase.FRM will exist. Rename this to a different name: you will have to rename it back to mybase.FRM at the end of the rebuilding process.
  3. Make a safety copy of mybase.FMT under a different name. This will act as a backup if something goes wrong with the rebuilding process.
  4. If you are rebuilding the format file in order to allow it to grow beyond the 8MB limit, then do the following:


  1. Make sure that your copy of Cardbox is closed.
  2. Rename mybase.FMT to mybase.FRM. No file called mybase.FMT should now exist.
  3. Start Cardbox. If you had mybase.FIL open before, then Cardbox will report an error when trying to re-open it. Do not worry: acknowledge this error, and continue.
  4. Use Cardbox's File, Open command to open mybase.FIL. Cardbox will warn you that mybase.FMT does not exist, and offer to build it from mybase.FRM. Say Yes to this.
  5. The format file will now be rebuilt.

After rebuilding

  1. Keep the old copy of the format file that you made at the beginning, as a backup; but erase mybase.FRM.
  2. If you had an old mybase.FRM (for Cardbox-Plus) and renamed it at the beginning, then rename it back to mybase.FRM now.
  3. If you made the change to CBOX.INI, there is no harm in keeping it.

Technical notes
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