Registration is a bit of a mess... Usually when the register dialog comes up and shows giveaway... for the email address you leave it alone and it works. When I did that it did not register, plus, it locked out the registration dialog so I could not try again. Luckily I was using a VM, so I tried again with another VM, using the same email & key. This time it said the key was already used, So I went to get another key using a different email address, and that was blocked because I was using the same IP address. Fired up a VPN, tried again, got the key, filled in the email & key, and this time it maybe worked -- I'm not sure because it showed the first email address I'd entered with the new key. The register dialog was locked, and the About window didn't say if it was registered or not. Went back to the 1st VM to double check and compare what the registration dialog said, only now clicking register crashed the app. OK, so I copied the program's folder to my regular copy of Windows, got another key using another VPN & email address, ran the app, and this time got a Trial dialog, clicked register, entered the email & key, and got the same registration dialog I'd seen earlier, but showing giveaway... for the email address.
At any rate, installing Aiseesoft Data Recovery 2.1.16 adds the program's folder to Program Files (x86), along with a new folder is Users\ [UserName]\ AppData\ Local\. The registry gets several keys/entries related to registration & whether to show the initial giveaway registration window, but otherwise just one key for the app & one for uninstall are all that's added. The program window was oversized on this display, which is set to Scale 150%, but setting compatibility to Change high DPI settings -> Override high DPI... -> System fixed that. DJ has posted asking if there's a way to make it portable. I don't believe so since the program uses a hardware key, so transferring everything [including that key] to another copy of Windows it will display the trial dialog, so even if you use an app or script to create the necessary registry entries it would not work.