Heavily compressing textures and lowering the resolution of in-game videos.
Highly compressed files are prone to "CRC Errors" or "ISDone.dll" errors during installation. If one tiny bit of data is corrupted during the download, the entire installation will fail. Safety and Security Warnings
Always check user comments and use a virus scanner before executing any .exe or .bat files from these sources. System Requirements (Minimum)
Using powerful compression algorithms like LZMA2 or special tools like SREP and Precomp. The Realities of Using a 305MB Repack