To correct that with Windows Vista and 7:
1/ In the Start menu select Accessories > right click on Notepad and select to start as administrator
2/ In the Notepad select File > Open > navigate to C:/ > Windows > System32 > drivers > etc
3/ Select in Notepad to show all files bottom right instead .txt files only, open the hosts file you'll see

If you see entries for gaytor.rent and gtru.net, just put an # sign in front of them or delete those line.

Save the file, which will only possible if you opened notepad with right mouse click as administrator as said upstairs.

ATTENTION: Do NOT touch any other entries, wrong manipulation may result in loosing internet navigation.

For Mac users, in the Terminal type:

sudo nano /private/etc/hosts

Then use the editor "nano" to change that file.