The first PC version of Resident Evil 4 (often called the SourceNext port) was infamous for launching with absolutely no mouse support TechPowerUp
Problem: No cursor / mouse input not recognized Download Resident Evil 4 Pc Mouse Support
When you search for "download Resident Evil 4 PC mouse support," you will find shady websites offering "auto-aim bots" or "mouse injectors." Be careful. The first PC version of Resident Evil 4