I have tried to download the [Denodo Express 8.0](https://community.denodo.com/express/download/) Windows 64-bit installer and it is working fine for me.
For this scenario, I would suggest you connect from a network which supports faster download/uninterrupted internet connection so that your download does not fail in the intermediate step.
Alternatively, if you are connected on VPN then try to disconnect the connection and download Denodo Express again.
You can refer to the similar [community question](https://community.denodo.com/answers/question/details?questionId=9060g000000L6iMAAS&title=Unable+to+download+denodo+installer+file) for more information.
Hope this helps !