When DTPlugin want to autoinstall JavaFX into system, we failed to update DTdll because DT is running. We want to avoid this File-in-use cases. Installation: update DT registries to latest DTdll in DeployDir. The next time Browser launches, it will use latest DTdlls. Uninstallation: We still want to keep DTdlls in system. We copy DTdlls that's going to removed from system to system32 directory and update browser registry to point to system32/DTdll.