Well, there you go. The file is owned by root and you don't have permission to write to it.
It also has the superuser immutable flag set so only root can change the file.
How did you get it there?
hosts 2 means nothing and no reason any hosts file would be on your Desktop.
You should be able to delete it using Terminal, but be careful.
Enter this with the space after it, then drag the hosts 2 file into the Terminal window. It will fill out the path to the file.
sudo rm -i
After making sure it is only going to delete that file, hit return.
sudo will ask for your admin password. Enter it and hit return. It will not echo any characters to the screen when you type.
When it runs, it will ask if you really want to delete that file. Again, make sure it isn't going to delete something else, then type y to confirm delete.