As @lisasc360 mentioned, when this happens, Internet Explorer, no matter what browser you use, must be cleared. The privacy settings must be reset and the box to clear all personal settings must be checked.
bring up Internet Explorer.
Click on the tools icon (3d from left, 2d from right)
Choose "Internet Options"
Click on the Advanced tab (last tab on the very right)
Click on RESET
A pop-up box then has a box in it to check - Delete Personal Settings
Then click on the RESET
This will reset Internet Explorer and should then let you log in.
Whenever you have this problem with the launcher and logging in, do this.
