When you launch pes2013.exe , the system checks a specific "path" in the Windows Registry. If that path is missing or points to the wrong folder, the game assumes it isn't installed. On a 32-bit (x86) system, the registry structure is slightly different than on 64-bit systems, which is why generic "registry fixes" found online often fail. Step-by-Step Guide: Creating the 32-bit Registry File
to match where your PES 2013 is actually installed.
When you see an error like “PES 2013 has not been installed” or “Registry entry missing” , the game is trying to locate paths like:
If the game was moved to a new drive or installed without a formal installer, you can create a .reg file to restore functionality. and paste the following code: