How to block website

I want to block certain website from my computer. How could it be possible ? I am using windows XP.

Thank you.

If you want to block access to some site from your computer, you can do it in file called hosts. It should be placed in c:\WINDOWS\system32\drivers\etc\ and it should contain something like 127.0.0.1 localhost. So just add 127.0.0.1 and the name of the sie you want to block. For example idnes.cz

That should do the job.