hosts file is a text file used to map IP addresses to hostname before DNS was in place. So you will ask why to edit it?
Simple – sometimes is required to have map if specific host to different IP ( for example: testing ).
In general is not recommended to edit hosts file. Even some viruses are using it to map popular antivirus sites to localhost and hence deny access to them.
The file is located in %systemroot%\system32\drivers\etc\ (which for most of computers translate to C:\windows\system32\drivers\etc\)
In Windows XP and lower if you are logged as administrator you can edit the file directly, but to increase security (since most of ordinary users log as administrators) Microsoft decided to add in Windows Vista (and newer) additional layer of security so you are unable to edit the file directly.
Here is how to do it:
- In Start menu type Notepad
- Right click on Notepad and select run as Administrator
- Continue as usual – edit the file and save it
Note: Some antivirus products “protect” hosts file so you might need to disable that protection before editing.
Note: For newbies the format of the file is following:
Where x.x.x.x is IP address in numeric form
and FQDN is Fully Qualified Domain Name