This application note only applies to DX4WIN version 9.

When you update DX4WIN using Help | Check for Updates, DX4WIN will move any old files that it replaces to a Backups folder (directory). Here is an example showing the folder/file hierarchy:

E:\dx4w903
10/30/2025 15:50 ├──Backups
09/07/2020 06:21 │ ├──1
08/31/2020 21:14 │ │ ├ country.dat
08/31/2020 21:15 │ │ └ members.dat
09/17/2020 21:17 │ ├──2
08/31/2020 06:41 │ │ ├ clusters.txt
08/31/2020 06:41 │ │ ├ mstrcals.dat
08/31/2020 06:41 │ │ ├ calendar.dat
09/10/2020 13:42 │ │ └ members.dat

DX4WIN creates a new numerical folder under the Backups folder each time you update, starting with number 1.

David, K2DBK reported that he had 3 GB (gigabytes) of backup data. Jim, AD1C had about 2.3 GB of backup data on one computer and 2.6 GB of backup data on another. If you are not having problems with DX4WIN, you may want to delete some or all of the directories under Backups.

Using File Explorer, navigate to your dx4w9##\Backups folder. I recommend deleting all but the most recent five numerical folders. Remember that in Windows, you can use the Shift and Control keys to select multiple folders at once. Just be careful to delete only directories inside the Backups folder.