LocalApphelp

LocalApphelp is a component of the Microsoft Windows operating system. Its primary function is to provide application compatibility support for older programs that may not run correctly on newer versions of Windows. When an application is launched, LocalApphelp checks if it requires any specific compatibility fixes or shims to operate. These shims are small pieces of code that intercept and modify certain application calls to the operating system, effectively tricking the older application into believing it is running on an older, compatible operating system.

The LocalApphelp service is part of the Application Compatibility Infrastructure. It works in conjunction with Application Compatibility Toolkit (ACT) which allows IT professionals to test and deploy compatibility fixes. For end-users, LocalApphelp operates largely in the background, automatically applying necessary adjustments without explicit user intervention. This allows a wide range of legacy software to continue functioning on modern Windows platforms, reducing the need for users to upgrade their software or migrate to virtual machines for older applications. The service is designed to be efficient and generally has a minimal impact on system performance. While primarily focused on compatibility, it also plays a role in reporting application failures, which can aid in diagnosing and resolving issues.