I've registered mIRC on both 32 and 64bit versions of Vista without problems.
Did you run setup as Administrator or normally?
Yup, I've got v6.35
Again, the validation error could be a server issue or it could be a problem with your license. You should e-mail Khaled in this case.
I did. I'm looking forward to his reply.
PS A thought occurs... how does mIRC make contact with the web site? Could my firewall be blocking it? What protocol/port does it use?