Hi JD,
Please cross check whether following server roles are enabled in the server
- Webserver(IIS)
- Webserver
(default selection plus Application development - enable from CGI upto Websocket protocol)
- Management Tools(all of them including IIS 6 compatibility)
After installing required roles restart your server and run WebSiteManCS.exe (\SAP\CS Tool)
Let me know the result.
Thanks and regards,
Jayadeep