Assuming you use windoze ...
Open a command prompt [COMMAND <= find programs] and check your DNS Server (see if it is caused by the browser, system or your ISP's [or other] DNS):
Code:
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.
C:\Users\Owner>nslookup gfy.com
Server: google-public-dns-a.google.com
Address: 8.8.8.8
Non-authoritative answer:
Name: gfy.com
Address: 4.28.42.196
C:\Users\Owner>