A Windows machine can access the registry of a remote Windows machine if the Windows Remote Registry Service is started on the destination machine and permissions allow.

When MACHINE_A connects to the registry of SERVER_B all registry access is transparent. After connecting, all Windows Registry APIs work identically when accessing information on SERVER_B as they do when accessing information in the local registry.

When Windows is installed on a server with 64-bit hardware, Microsoft supports running 32-bit applications.

When a 32-bit application running on a 64-bit machine accesses the \SOFTWARE branch of the registry, though, Microsoft inserts an extra subkey element into the subkey name (\Wow6432Node).

In general, this is transparent to applications through an approach Microsoft calls reflection.

An important exception is when a 32-bit Windows XP machine accesses the \SOFTWARE branch of the registry on a 64-bit server. In this situation, Microsoft’s insertion of the \Wow6432Node subkey into the actual name of the registry subkey is not transparent.

Applications running on a 32-bit Windows XP machine that access the registry of a 64-bit Windows server must insert the \Wow6432Node element into the subkey name.

Argent applications address this.

Argent has developed a reference application named ARGSOFT_REG_TESTER.EXE that can be used to verify remote registry access from one Windows machine to another.