Help pls!!! avast! home edition query.

Hello,

How do I get Avant! Home Edition into my pc? I've just reformatted my pc, so there is no other anti-virus installed yet. I've been trying to get Avant! Home Edition since early morning today, but all I get are downloads from cnet.com. If I try to open or run the file...it works only up to a few screens but never gets to the point of installation. I am really losing my temper on this, please help me before I lose my sanity!!!

Thank you.