All the free downloads of Proteus 7 (now at v8) that I could find had a string attached, like:
http://wiseconvert.com/tos/

Basically saying "We're giving you this older version BUT you have to install our POS software that has 3rd party software that may do anything they please to your PC, you, and your decendants for 10 generations."

I think I'll pass.

Robert