LocalServer32

LocalServer32 is a registry-based mechanism used by the Windows Component Object Model (COM) to locate and start out-of-process 32-bit servers. Specifically, the LocalServer32 value is stored under a CLSID (Class Identifier) key in the Windows registry and holds the path to the executable that should be launched to host the COM server when a client requests the corresponding class. This value distinguishes out-of-process servers from in-process servers, which use the InprocServer32 entry to indicate a DLL.

On 64-bit Windows, there is also a LocalServer64 value for out-of-process 64-bit servers. When a 32-bit client creates a COM object whose server is registered with LocalServer32, the COM runtime launches the designated executable in a separate process and communicates with it via COM marshaling. The path can include command-line arguments, and paths with spaces are typically quoted.

If the executable cannot be found or the registry value is misconfigured, COM activation will fail for that class. LocalServer32 entries are commonly used by software that implements out-of-process functionality, such as helper utilities or host processes. They can be legitimate, but if altered by malware, they may be used to run arbitrary code during activation, so keeping registrations trustworthy is important.

For comparison, in-process servers use InprocServer32 (a DLL), while LocalServer32 specifies an external executable. Related registry entries include LocalServer64 for 64-bit servers on 64-bit systems and the InprocServer32 key for in-process DLL servers. Understanding LocalServer32 is helpful when troubleshooting COM activation issues, software installation, or DCOM configuration.