1. Go to C:\Windows\System32\drivers\etc now you can see some files are there and double click on hosts file and open it with notepad.
And save it . But if you are windows7 user then it will not allow you to make a change in that file , and I have also solution for that .
3. Right click on hosts file and select security tab (I have hide my user name)
4. Now select USERS after that click on EDIT
5. You can see one dialog box will open and in that select users
6. Now you can see we don’t have write permission now just select full control.
7.After that just simply click OK
8.And one dialog box will open will in that just press yes.
Now you can save hosts file in windows 7/8. and after that add this serial key.
and click ok and you have done !
you can see my full version of IDM