If blender is unzipped, run it as administrator to install the addon.
Another workaround is to manually create a folder for the addon and copy the files into it within your addons.
It should be c:\Users[yourname!]\AppData\Roaming/Blender Foundation\Blender\2.8\scripts\addons\bonebreaker
If the folder does not exist you can manually create it and unzip the files there.
After that it should show up within your addon panel just fine.
Again, installing while running as administrator will probably do this for you.
All that said, hopefully people won’t have those issue once 2.8 goes live.
If you continue to have troubles with blender I suggest asking @ BlenderArtists about it. They will probably respond more accurately and faster than me…