I don't know what is previous mSecure version our client used but I have mSecure.mscw file and backup files
How can I restore these file to new mSecure?
it looks like I have to download 3.5.7 version and migrate to new version.
A .mscx file is an old backup file created in mSecure 3. You can download mSecure 3 for Mac or Windows in order to be able to restore from that backup file. You can download mSecure 3 for Windows here: https://support.msecure.com/en/support/solutions/articles/36000022199
In order to restore from a backup file in mSecure 3, make sure to set up a lock password and follow these steps: