Starting February 1, you can get the free Angry Birds for PC for free. The offer will run for 15,000 downloads, or until the end of March, via the Intel AppUp PC App Store. To get the download of Angry Birds PC, just sign up for an account with Intel AppUp

1. Go to this link
2. Download Intel app from that link, not from Intel site
3. Install that app
4. Register for a new account from the app

5. Angry Birds will show up in your 'My Apps' tab in the Intel app

If it doesn't show up in your "My Apps" tab right away, it's because their servers are getting hammered. Try clicking on the Angry Birds "buy now" button from the store, it should just start downloading.