Adobe Acrobat Reader will not install

When I try to install Adobe Acrobat Reader DC, I get a message that a newer version is already installed, and then a second message that the install failed.

The website suggests that I uninstall the program and then re-install it, but I have tried that.  My computer does not list the program as being on it, and pdf files open with word, not Adobe Acrobat Reader DC.

Any helpful suggestion would be appreciated.