Please check this video where I'm explaining in depth what needs to be done to register the add-in: https://www.youtube.com/watch?v=5Qy7KKy8-fE
If you are using COM based add-in you need to use RegSvr32 utility instead of RegAsm.
You can also take a look at this article which explains how to create a msi-installer: http://help.solidworks.com/2013/English/api/sldworksapiprogguide/miscellaneous/create_setup_project_to_distribute_solidworks_add-in.htm
Regards, Artem Taturevych | Snr. Developer | IC3D ANZ
IC3DSteel – New Steel Solution for SolidWorks
translationXpert – SolidWorks files language translator
Attached are two simple scripts I typically use for manually registering .NET dll assemblies.
Open the scripts in notepad and read the remarks for more info (you need to add the path to your dll).
If you get an error when registering, you probably have something wrong with your ComRegisterFunction or ComUnregisterFunction in your Addin. I have also attached a sample SwAddin.vb (sorry don't have a C# sample) with a correct implementation of this.
Hope this helps,
RegUnreg.zip 49.0 KB