Problem
After entering in the proper credentials to activate a product, the buttons to proceed to not respond to clicks.
Solution
There are components of IE (Internet Explorer) in that window. If you have restrictions on IE (some do), the 'Activate' but may fail to respond to clicks. The options are:
Set Internet Options to its default settings
Do a search for ‘Internet Options'
Security → Medium → Apply →
Use the command line to activate
An alternate option would be to use the command line activation method.
Click here to see command line activation directions
Note: This method will not work for a trial - only for the paid version of the product.