Where to download 64bit SEP 12.1 trial?

I'm trying to download a SEP 12.1 unmanaged client trial for our server which is 64 bit.

I registered and found a download, which wouldn't install because it said it was incompatible with the computer architecture. I know if you try and install 64 bit software on a 32 bit machine, but I thought it was usually ok the other way around.

Anyway, can anyone point me to where I can download a trial of 64-bit SEM 12.1 for an unmanaged client please because I've been searching for hours and the Symantec website is making my head spin!

Thanks