Grand Theft Auto 5 does not currently exist, nor has it been announced. Keep this in mind if you happen to stumble across a supposed "leaked" copy of the game for Windows, as one such torrent has infected thousands of PCs with malware.
The alleged PC version of Grand Theft Auto 5 offered up in a public torrent is around 18 GB in size and has been falsely verified as legitimate, making it seem like the real deal. Once the download completes and the installer is launched, however, malicious software is deployed without the user's knowledge. Torrenters are then instructed to fill out a series of online surveys in order to claim a nonexistent registration key, lining the pockets of scammers in the process.
WCCFTech notes that the torrent in question has been downloaded thousands of times, likely compromising thousands of unsuspecting victims. Don't let your hype for a PC release for Grand Theft Auto 5 override your common sense, as the consequences could be dire.