In order to perform Silent Uninstallation of the Denodo Platform (Virtual DataPort Client , in your case), I would execute the below command as an Administrator user in the Command Line:
java -jar <DENODO_HOME>/Uninstaller/denodo-uninstall-7.0.jar -c
Also, before executing the command I would make sure that all instances of Microsoft Internet Explorer are closed and all the Denodo Servers are stopped.
For more details, take a look at the Knowledge Base Article **[Headless Installation](https://community.denodo.com/kb/view/document/Headless%20installation?category=Installation+%26+Updates)**.
Hope this helps!