Hello Luis,
AxCrypt encrypted files should have a file extension “.axx”. Also, default application for the file type “.axx” should be AxCrypt app only.
Might be, the default application is not mapped for the file extension “.axx” in your system. So please change the default application to AxCrypt for the file extension for “.axx” with the help of following links,
https://support.microsoft.com/en-us/help/4028161/windows-10-change-default-programs or https://support.microsoft.com/en-us/help/18539/windows-7-change-default-programs
Now all the encrypted files with the file extension ‘.axx’ will be opened by double clicking the file.
If the above does not help,please provide more information about the issue and write a mail to support@axcrypt.net .