I asked Bitdefender for tech support and they said they block untrusted executable files from running if they’re not trusted by Windows Smartscreen. They said that Smartscreen intercepts suspicious files first and then the antivirus blocks any attempts to run it. I’m not a very technical user but I think I understand what has happened.
I downloaded my Axcrypt self decrypt backup from Google Drive onto my Windows 7 computer when a friend suggested I do that and it worked on there. I then copied the files onto a USB and onto my Windows 10 computer and it worked :)
I’ve sent the screenshot that you asked for.
When I was speaking to Bitdefender they asked me to email them a copy of that file for analysis. I asked a technical friend about Windows Authenticode and he said that it’s not difficult for people to obtain fake certificates or modify rogue software to bear a real certificate. He said that a lot of software has asc/has signatures and I should check these instead.
I can’t remember where I downloaded it from but it was probably Filehippo or CNET because the download on here wasn’t working and kept redirecting me. The Axcrypt website download is working now and I have all my files back I’m pleased to say.
Thanks for helping me.