Windows 7 won’t allow you to modify hosts file, even you are logged in as administrator. Hosts file can be found in C:\Windows\System32\drivers\etc. Even if you cleared read-only flag in file properites, file can’t be saved. Message would come up as:
You don’t have permission to save in this location. Contact the administrator to obtain permission.
Workaround is very simple. Administrated privileges need to be given to notepad.exe program before you open hosts file.
Simple type notepad in Run. Right click it and select Run as Administrator. Now you will be able to save file after modification.