A typical "Mod-Friendly" build of San Andreas usually includes several critical components that go beyond the base game files:
Ensure this file is present. Right-click it, go to Properties > Compatibility, and set it to "Run this program as an administrator." Grand-Theft-Auto-San-Andreas-Mod-Friendly.7z
A patch that allows the game to utilize more than 2GB of RAM, preventing the "Memory Full" crashes that occur when you install high-definition texture packs. Step-by-Step: How to Use the .7z File A typical "Mod-Friendly" build of San Andreas usually