PS CC requests serial, can't find .hosts file on Win 8.1

[Archaotic]

Well, that's pretty much it.
I can't use Photoshop because it keeps bugging me with "enter serial". I looked about for advice, and did all the most commonly suggested things (language, security settings etc.) BUT when it comes to resetting the .hosts file --well, damn. I cannot find it anywhere. Or, to be more precise, there is one file named .hosts in my system32/etc folder, but when I open it, all I get is a a few lines of text explaining that "This is a sample HOSTS file used by Microsoft TCP/IP for Windows" and instructions on how to edit such a file. There are no actual host entries, or anything else for that matter, so I can't do anything with it.
So... what am I missing? I haven't had Windows 8.1 for long and I'm not all that familiar with it yet. It's just so damn irritiating when I can't do any work, and can't use the software I'm paying for

[Mylenium · Accepted solution]

Sign in, activation, or connection errors | CS5.5 and later

Mylenium

[Archaotic]

Still doesn't work. I don't get any of those errors either --only the "your trial has expired" -message or the serial/activation code request, for whatever reason.

[Jeffrey_A_Wright]

Archaotic did you have any questions regarding the steps listed by Mylenium?  You have an active membership.  If the computer is unable to communicate with our activation server then your membership will not be authorized and the Adobe Creative applications will not be authorized.