are you trying to install web server or a webs server client?
If you already have EPDM WEB SERVER Online.
1. Just go to the Web addresse of your EPDM Web Server.
2. Enable all activeX Controls.
3. If you still face any problem you can manually install Web Client using install.msi found in Your Server (Where you installed EPDM) somewere in c/prog files/epdm/web/install/install.msi....i dont have epdm right now.
Take the whole WEB Folder and run install.msi