can't upgrade from 2.0 to 2.5 - keeps reverting back

I'm having problems. I'm a personal user, for whom this is supposed to be a free program. My version (2.0) started telling me it was about to expire and I'd have to try to launch it multiple times before it would finally start. I thought I'd try upgrading to the latest version, but it won't upgrade. I even uninstalled 2.0 and deleted the SmartFTP registry settings, but all that did was lose my settings. I installed 2.5 again and again, but when I launch the program (after trying multiple times) it says I'm still running 2.0. I right-click on the executable, look at the version tab, and indeed it's 2.0 - I don't know where it's getting the old file, or why. And the program still won't launch immediately - tells me it's about to expire, and I have to click the icon multiple times before it will launch.

Why is this program torturing me? Why will it not launch? Why will it not upgrade? I hope someone answers this message.

Thank you.

You can install the latest version from:
https://www.smartftp.com/download

The reason you believe it's "reverting back" is because you are still starting version 2.0 after you have installed version 2.5.
You may want to remove both versions (2.5 and 2.0) before you install the latest version.

Regards,
Mat