>An old client just surfaced with some problems. I used Cryptor 5 to give him the encryption he wanted in the application.
>Since I last did anything for him, I've switched to a 64-bit Windows 7 machine. I'm now trying to register Cryptor, so that I can run this application.
...
>Any suggestions?

not really - large former client switched away from Cryptor in 2011 because of OS problems.
I was not involved, so no further data, but them switching means they also ran into trouble,
as they already payed he license and are ***not*** one to swap just for the fun of it...

HTH

thomas