Several years ago without advance notice, Ubisoft allowed a free download of the game for only one day.
Ubisoft did not mention that the download was restricted to only people who lived in the United States.
Ubisoft did not mention that the special download required authentication via an Internet connection to a server of Ubisoft.
Ubisoft has permanently turned off that particular server promotion.
Various software sharing Websites have allowed people to place that download for people such as you to download and complain that the software does not work.
Sorry. You got for what you paid.
You should complain to the file sharing Website that the software is worthless and should be removed from the Website.
Ubisoft sold a three-pack trilogy of Sands of Time, Warrior Within, and The Two Thrones.
Try to purchase a valid box version of the game off of a "games for sale" Website.
You might find a copy at a store that sells video games.