Since Pro Skater HD is no longer supported, most fans have moved to the newer, more critically acclaimed remakes: Tony Hawk's™ Pro Skater™ 1 + 2 on Steam
The game was "retired" primarily due to . Licensing for iconic soundtracks and professional skaters often has a set duration; once it expires, the publisher (Activision) loses the legal right to sell the game. Official Alternatives Tony Hawk’s Pro Skater HD Free Download
If you are looking to play the classic levels in high definition, here is the current status and the best alternatives: Why It Was Removed Since Pro Skater HD is no longer supported,