You may need a costly (or even free) software to block such websites.
Why to spend money and time and why give HDD space to such useless softwares.
Just do this and block unwanted softwares from accesing.
1] Browse C:\WINDOWS\system32\drivers\etc
2] Find the file named "HOSTS"
3] Open it in notepad
4] Under "127.0.0.1 localhost" Add 127.0.0.2 www.xyz.com , and that site will no longer be accessable.
-->www.blockedsite.com is now unaccessable<-- For every site after that you want to add, just add "1" to the last number in the internal ip (127.0.0.2) and then the add like before. i.e. 127.0.0.3 www.abc.com 127.0.0.4 www.anysite.com 127.0.0.5 www.blahblah.com etc * To unblock sites just do the vice versa !