Are you using the IE version of the overlay because you don't have 64 bit Windows? What version of IE are you using?
Open your IE browser
, click the cog icon on the top right corner, choose "Internet Options", on the General tab look at "Browsing history" and click the "Delete..." button, checkmark "Temporary Internet files" and "Cookies and website data" then press the "Delete" button. Then try and start the overlay.
Can you give me a screenshot of the overlay?