Advice 1: How to prevent the transition to the websites

Often when using the world wide web, the need arises to block access to certain resources or resource groups. Reasons for this may be many, but it is worth remembering that the procedure of banning sites is quite easy and does not cause any problems.
How to prevent the transition to the websites
In order to block access to certain sites, edit the hosts file located at c:\windows\system32\drivers\etc\. This document contains the DNS names of banned resources, so placing him the addresses, you will prevent the visit unwanted websites from your computer. This mechanism is relevant only for one PC, and in that case, if a blocked site, there are mirrors, you must make an entry in the host e for each mirror individually.
Use the method of IP blocking. To do this, create a list of IP addresses of sites with illegal access to a specific computer, thus you will ensure the lock using the software firewall. However, this method to block a website by the name would be impossible. Do not forget about the method using the proxy server. The essence is to create "black lists" of sites in the software settings of the proxy server. When using this method, you indicate "stop words" in URLs, to which access want to close. The inferiority of this method is the forced browser setting and the ability of the users to visit the forbidden resources, bypassing the proxy server.
Also use method of URL filtering. Great flexibility and good effect of this method is very different from the previous one. The analysis of each network resource is the essence of the process URL filtering. If found, the header of the WEB request that contains the url of the site you want to block, it performs the following operations:

1) is blocked by the network resource with the client request;
2) the client sends a message "Access blocked";
3) terminates TCP connection.

To use this method to the value of the filter type prohibited requests and save the changes. URL filter can block access to any website by name, to prevent downloading the file by their extension and also create a list of approved sites and deny access to others.

Advice 2 : How to deny access to the website from a computer

Not all Internet resources are equally useful and safe, especially for children, so the prohibition of access - a very useful function which in some cases have to use.
How to deny access to the website from a computer
To prohibit the entrance to any website, open the menu "start".
Click "Run" (Run...).
Enter into the directory this way: "C:\Windows\System32\drivers\etc" (in windows 2000 "C:\WINNT\System32\drivers\etc"). Press the Enter key.
In the opened folder, locate the hosts file. Open it with any text editor, such as Notepad. You will open the document with the "guts" of the hosts file.
In this file find the line with IP, for example localhost. To deny access, for example, to the VK site, put the cursor at the end of the word localhost (or the end of the row you last) and press Enter.
Move the cursor to a new line and specify the following: Click on the keyboard Tab, you should see the indentation more than a space. Write the website address without http and Keshev (/), like this -

Write the following:
In the same way, we can proceed with "Classmates". Do all of the above points, you should get this:

Numbers on the left – the internal ip address of your computer, right — the names of the domains to which you want to block the way.
For the changes to apply, then save the file (click "File", then click on "Save") and then restart the computer. Then when you request a blocked site, the browser will navigate to another page (error access denied).

Thus, to connect to a given site will fail and the page will not load. If your computer are people who know what is the hosts file, you can just put a password on the folder which contains this file.
In the web browser Opera to prohibit the entrance to the site in a different way. Select "Tools", which is the top of the browser.
Select "Advanced" from the list.
From the new list select "Blocked content".
In the window that appears, enter the names of the sites to which you want to deny access.
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