I'm thinking of buying Webdesign 10 Premium because it looks like a great product as I'm using the demo at the momnet with the 32bit version, so it can be compatible with my operating system and I'm planning on doing an upgrade to 64bit with my whole system soon;

and being a newbie I wanted to know before I make the purchase if if it is possible to just download the 64bit after I have purchased the 32bit, or do I have to buy a new copy?

Or related to this, is it possible to run the 64bit software on 32bit operating system? or visa versa?