Error in attachment happens when installing Visual Studio 2015, anyone can help?
Welcome to the forums.
Try to find the log file that is written during the installation (and post it here?). It should contain more useful information about the actual error that happend (not just that there was an error). For example you could try to find that offending registry key and delete it manually. A restart might potentially get rid of “marked for deletion” registry keys so try that as well.
From the error message it appears to have happened during Microsoft .NET Framework 4.6.1 Developer Pack. So you could probably try to download and install that manually/seperately.