The option found in Store Commander > Tools > Intstallation > Change the security key, allows you to modify the security key used in Store Commander's directory to avoid any malicious access.
Modifying that security key used requires your license key to be reset, so that you can validate it when you restart Store Commander after the modification.
To do so, log onto your account www.storecommander.com > my licenses to click on the reset link under your license key.
You will then be able to enter your license key in the welcome form when launching Store Commander from Modules menu.
Everyone currently using SC when you apply the modification will need to restart Store Commander from the backoffice > Modules. Remember to let the users know!
If CRON tasks are in place, remember to change the URL path in the tasks configuration files. The new path is visible in the address bar of your internet browser when Store Commander will be relaunched.