I found those files and deleted them.
I installed AxCrypt and it worked the first time (yay!), but when I tried another encrypted file it didn’t start the program.
So I restarted my PC, tried to open an encrypted file and was prompted for an email address, entered it and the program froze and will not open again (even if I try “Run as administrator”). (I checked that those DLL files had not been re-made – they had not).
Restarted PC again opened AxCrypt and got dialogue box saying:
“An unexpected Error -‘The requested service provider could not be loaded or initialized’ occurred”
(This box will not go when I click ‘OK’ either).