After some searching, steam user @KieSeyHow help everyone out with this issue that occurs when you have a CPU with more than 4 cores.

For this fix you have to run Steam itself with a custom shortcut.

BONUS: This tweak actually fixed startup crashes on a few other old classic games also! older games don't run any faster on more than the first 8 logical cores anyways. Four cores with hyperthreading gives you 8 logical cores. By limiting the main Steam Launcher itself with a custom shortcut, all other Steam assets inherit the same settings which greatly inproves compantibility with older games.

So let's start:

1. Go to your Steam's directory, by default:
   C:\Program Files (x86)\Steam\Steam.exe
   and create a desktop shortcut of steam.exe pressing:
   Right Click --> Send to --> Desktop (Create Shortcut).
   
   
2. Right-click that NEW shortcut and select "Properties" from the mouse context menu.
   
   
3. In the box marked "Target" add BEFORE C:\YourSteamPath\Steam\Steam.exe the following line:
   
   C:\Windows\System32\cmd.exe /C start "steam" /affinity 0xff
   
   The resulting Target path should look like this:
   
   C:\Windows\System32\cmd.exe /C start "steam" /affinity 0xff "C:\YourSteamPath\Steam\steam.exe"
   
   
4. Launch Steam with your custom shortcut, then start the Prototype game from inside the Steam library.
   
   Your new shortcut should look with a cmd icon after all this steps. So, before playing the game, close steam if you have it opened already and use always this new shortcut we just created.
   
   

If the game resolution is lower than your desktop resolution, try this:

1. Download Prototype.all.Resolutions.and.higher.FOV.7z[community.pcgamingwiki.com].
   The file is from pcgamingwiki so the password for that .7z file is: pcgw
   
   
2. Choose one .dll from the folders with your desired FOV config that better fits you. You can choose from Original/ Higher/ Even Higher FOV.
   
   
3. Extract the prototypeenginef.dll to the installation game folder and replace the original file.

Preview of some of the FOV options:

Original FOV

Higher FOV

This addresses the stuttering sounds and crashing that may happen in many old games because of an incompatibility between how sounds are buffered in newer 64bit systems, compared to older 32bit systems the devs used years ago. It's basically a compatibility tweak.

In Windows open your audio properties for your sound card. Change the advanced audio properties, on your "default" "playback device", to 44khz instead of 48, 96, or whatever it says.



Now, open the game and go to the sound settings and change the latency to 32ms, click Save then Back