Or, like i said, get Norton 360 for "cheap". I can PM you a link if you need.
Somehow, I wouldn't trust a pirated version of an anti-virus.
And somehow, i would never pay for any software. And many people i know uses pirated versions of AV without any probs. The AVs are very loyal even when pirated. You can also use their "One-click support" feature and they won't know you have a pirated copy.
You don't
know of any problems, which is quite a different thing than not having any.
Personally, I'd prefer to use only open-source software, checksummed against official hashes and with releases signed by the developer's public key. Unfortunately, that's not going to happen if I want to get anything done, but my point still stands that running binaries that you know to be modified by shady sources with whom you have no legal recourse against is a Bad Idea(tm).