Only edit the registry if you are comfortable doing so. Back up your registry first.
The "v6.43 to v6.47" transition (specifically the 643x647z patch) is a maintenance release designed to improve stability and cross-compatibility between the Professional and Showroom versions of the software.
Only restore this file from an official software installation media or a trusted backup. Do not download pro100v643x647z from DLL download sites – they are often malware vectors.