Can't register Visual Studio 2013 Express: cookies /Javascript problem

Hi, I got VS 2013 Express with UE4, and because its 30-day evaluation period is coming to its end I wanted to register the product. However, when going to Help → Register product → Sign in I get a message saying “Sorry, we ran into a problem”, and something like this: “the explorer cookies or the Javascript code aren’t working as expected”.

I’ve tried disabling Firewall and browser extensions/complements, however it still doesn’t work. Does anybody know how to solve this? I’m possibly not the first one to encounter this issue.

Any suggestions?

Any ideas?