Since plug-ins are missing from the registry after the reset, either the plug-ins are actually missing from the PC or the vst scanner is failing. The vst scanner can fail if the plug-in paths in
Preferences > File > VST Settings are bad. The paths may not contain the plug-ins or the scanner could be scanning folders it should not be scanning for example "Shared Plugins." Or there are duplicate paths such as any folder under "C:\Program Files\VSTplugins" if "C:\Program Files\VSTplugins" is already in the scan path.