Hii Guys this is a bug in fileserve i think that it provides you always a premium account.
I you have not a premium account Don't worry i will Provide you...
you know about the cookies of fileserve yet i will explain
first Use  in Mozilla Browser www.mozilla.com/
1. Get a add on of Mozilla through mozilla website you can find it by simply searching in Google.
Add on name : EDIT COOKIES 1.0
2. Now make a free account on fileserve first.

www.fileserve.com

3 Open that account.

4. Afterwards go to tool option and click on Edit Cookies (' A new tab appears')


5. Write fileserve and do refresh.


6. It shows Entry with name PHPSESSID and COOKIE.

7. Just click on it. And Replace the PHPSESSID with the code given below.

8. then do a refresh. Hurray You got a Premium Account.

9.  If you again goes to free account then no need to worry just again do the same procedure with the same cookie. no need to change PHPSESSID use only that PHPSESSID again refresh now u will sucessfully get the premium.
10. if not do the same procedure by changing PHPSESSSID given below. 

Do for three or four times if luck is not working otherwise i get it in only first to second times.
Enjoy Premium.

PHPSESSID of Fileserve.

          PHPSESSID

          bd3us5l4lrkhbp1bjsbmjqv0m5

          PHPSESSID
          mpe98qud63hun72vovu6nvg1r0  it is tested by me infact i m using it for 3 months

          PHPSESSID
          88ejlcoat7t6i65u3hp433rsh2

          PHPSESSID
          neeac1pi0ibq9e5ti30noffkj5

          PHPSESSID
          f0u4eh9lgigcf5t7op5tljs1m6

Now this show that it will expire on that _-_-_ dont worry after expiry you do same procedure again get premium Account.