The game is available for download via torrent, but be aware that downloading copyrighted material without permission is illegal in many countries. Some popular torrent sites for downloading the game include:

Most fans currently play the game on PC through using software like RPCS3 (for PS3) or Xenia (for Xbox 360). Note that emulation requires a powerful PC to run smoothly. Best Alternatives for PC

If you want a native Transformers experience on PC, Transformers: Fall of Cybertron and Transformers: Rise of the Dark Spark were officially released for Windows, though they must now be sourced via physical discs or archive sites.