Welcome to the community. 
We do not recommend deactivating your antivirus, leaving you exposed to online threats. What we recommend is adding WeMod as an exception in your anti-virus before launching it/installing it.
Your installation issues could also be due to having an outdated or corrupted .NET framework.
See this thread here for the full troubleshooting steps that we recommend: I can’t Install WeMod / "There was a error installing the application" - #2 by Ravenfyre