Wow.. I'm really stumped here.
After a successful install the res_mods folder should contain the following folders ... 0.9.15.1, configs, and mods. All those folder should have an assortment folders and/or files.
It sounds like your system is not letting the installer create the necessary files and folders.
Have you tried to download a new copy of the installer?
Someone else had mentioned creating an exception in you anti-virus software. <-- Is an excellent idea.