Try to uninstall the app. Please follow the steps below:
1 Open the Task Manager [right-click on the task bar > Start Task manager http://i.imgur.com/tNxdono.png
Close ALL LiveChat processes you can find: http://i.imgur.com/vMwAPKm.png]
2 Open Control Panel > Programs and Features. Find and remove all LiveChat installations you can find.
3 Delete all the files and folders with “LiveChat” in name from C:\Users<user name>\AppData\Local AND C:\Users<user name>\AppData\Roaming.
NOTE: You have to enable displaying of hidden folders in your Windows. Here’s how to do it: http://windows.microsoft.com/en-us/windows/show-hidden-files#show-hidden-files=windows-7
4 Remove all files from the following location:
5 Download the app from here: https://www.livechat.com/download/Windows/LiveChat.msi and install it on your PC
Show hidden files - Windows Help
Learn how to display hidden files, folders, and drives.
This should help. If not please contact me.