can't sign in to acrobat 11 trial

Hi, I'm trying to open a trial version of acrobat 11 but I can't get past the sign in for activation prompt. Keeps saying my computer can't access the internet. Ive tried offline activation but unable to generate a request code. Not sure how I would activate offline with a code anyhow as Acrobat only opens onto the login now screen.

Any help please would be great. thanks. Mark