How can I block certain Websites from being opened on my computer?

I am not positive that this will work with Windows 8 but it has worked for every flavor of Windows before it.

Look in C:\Windows\System32\drivers\etc for a file named hosts. It will have no extension and shouldn't.

Open it up with NotePad and you will see something like this.

The very last line is the line that does the work. 127.0.0.1 is the loopback address and the URL that is listed after it is the url that you don't want to open.

Add a line like this for any web site you don't want to open and save the file.

Now when you open up IE or Firefox and try to browse to that URL, the browser will get redirected to your loopback address and the requested URL will not work.

# Copyright (c) 1993-2009 Microsoft Corp.

#

# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.

#

# This file contains the mappings of IP addresses to host names. Each

# entry should be kept on an individual line. The IP address should

# be placed in the first column followed by the corresponding host name.

# The IP address and the host name should be separated by at least one

# space.

#

# Additionally, comments (such as these) may be inserted on individual

# lines or following the machine name denoted by a '#' symbol.

#

# For example:

#

# 102.54.94.97 rhino.acme.com # source server

# 38.25.63.10 x.acme.com # x client host

# localhost name resolution is handled within DNS itself.

# 127.0.0.1 localhost

# ::1 localhost

127.0.0.1 msntest.serving-sys.com

Avast! Free antivirus allows you to block sites on a Url basis

http://www.avast.com/en-ca/download-thank-you.php?...