Please try these solutions below to help solve your issue.

Default Browser:

Our activation windows are designed to work in Windows Internet Explorer (IE). If you do not have this installed, this is likely to be the cause. Please install Internet Explorer and try to activate the product again.

If you still are unable to activate your product, please make sure that Internet Explorer is your default browser and then try again. 

Lastly within Internet Explorer its worth moving the security slider to medium instead of medium high or high (Settings Cog > Internet Options > Security). The next tab is privacy so make sure the slider for that is at the bottom so it Accepts All Cookies. (Make sure the “Turn on Pop-up Blocker” is unticked. Click on apply then ok) 

Administrative Mode:

(Windows Vista/7/8 only) 

Running the whole installation in administrative mode has been known to solve this issue many times in the past. To do this, please right click on the installer application you have downloaded and select ‘Run as Administrator’ from the list of options.

Safe Mode:

As a last resort you can always try the running your PC in SafeMode with Networking then install the download? This is done when you start your PC up so you can try this guide by Microsoft:

http://windows.microsoft.com/en-US/windows7/Start-your-computer-in-safe-mode

Remember to select the SafeMode with Networking otherwise you won’t have internet access until you restart your PC and run it normally.