windows 8 and Ringcentral

Hi. I loaded Ringcentral in my new Toshiba that has Windows 8. Ringcentral worked after download, but after I shut down the computer Ringcentral could not be used again after start up. I uninstalled it, reloaded it again and the same thing happened again. It worked, but after shutting it down it would not operate on the next start up.
I don't get it. Is it a settings problem? Thanks for any help.