Problems installing Skype Web app

Hi everyone,

I'm trying to install the Microsoft Lync Web App Plugin.  I get to a point during the process where I'm prompted to run the plug in, in order to get audio and video.  However, as the progress bar gets to about 90% complete a dialogue box generates and indicates the "The specified account already exists", then closes and the users is never able to reach their meeting.

Here are some details surrounding the setup -

• The device is a Dell laptop

• The OS is a WIN 7 64-bit platform

• Running Microsoft Office 2013

• This is a domain environment

• The user is a standard user on the laptop

• I, as an admin, have installed the Skype Meetings App as I can see it listed in Control Panel

• I've also got the latest version of Silver Light installed

• I've also uninstalled and reinstalled the Skype Meetings App a couple times and get the same dialogue box - Account Already Exists

• I've cleared the cache and history

• We don't run Office 365

I'm a bit stumped.  Any thoughts?

Thanks for your help.