Hello! 
First of all, make sure you have the latest version of .NET Framework. Reformatting PCs, or sometimes installing a major update or new OS, either corrupts or does not re-install a new version of .NET Framework.
The link is under the last header in this post: I can’t Install WeMod / "There was a error installing the application" - #2 by Ravenfyre.
If this is not the case for you, see this post by @Veloxia: Download failed :( - #9 by Veloxia.