A batch file is an unformatted text file that contains one or more commands and has a .bat or .cmd file name extension.

To create one, you can use the Windows Notepad or Notepad++[notepad-plus-plus.org]. In this tutorial I'll be using the latter, but the procedure is the same.

• Create a new .txt file and insert the following in it:

• start steam://rungameid/271590 - starts Grand Theft Auto V through Steam
  
• timeout 120 - closes the batch file window 120 seconds after its been opened. This is to give your PC some time to launch the game, to then apply the priorities below to the processes. Change this to a higher value if your game doesn't open before this timer ends.
  
• wmic process where name="GTA5.exe" CALL setpriority "high priority" - set GTA5.exe to high priority
  
• wmic process where name=Launcher.exe" CALL setpriority "idle" - set GTA V's launcher to low priority (aka idle) - the Launcher itself will still work! Knowing this, the other lines below are self-explanatory.

• In Notepad, you need to save it with "All Files" selected, and then proceed to rename the file and add .bat to it.
• In Notepad++, you can save it as a batch file right away, as seen above.

Want to have the batch file in your desktop but dislike the ugly icon that comes with it? Then do this:

1. Put the batch file anywhere but the place you want to launch the game from (in my case, I put the batch file in my Steam\steamapps\common folder, while I launch the game from the shortcut in my desktop which I'll explain later).
2. Right-click it, press Send to and then Desktop (create shortcut).
3. Go to your desktop, right-click the shortcut, go to Proprieties and then the Shortcut tab. Press Change Icon..., then Browse... and find GTA5.exe, which should be in %ProgramFiles% (x86)\Steam\steamapps\common\Grand Theft Auto V\.


And there you have! Now launch your game through this shortcut (always Run as administrator) every time and it will be set to high CPU priority automatically.
If you have a nice processor, you probably don't need to do this, but hey, why not? Also, I've read that this helped people with weak CPUs/notebooks to have less stuttering, so why not give it a try? :)