ch version of Adobe Reader are you using? If you have installed skype on your system then there might be a conflict with the Skype Add-on for
Internet Explorer, so follow the below steps to rectify it:
Open Internet Explorer.
Click Tools -> Manage Add-ons -> Enable or Disable Add-ons.
In the list, click on Skype once.
Underneath, click the Disable radio button.
Click OK.
A message may appear saying you need to restart Internet Explorer. Click OK.
Close Internet Explorer.