You will need to consult with the computer's administrator first who obviously has set up some restrictions on it. Some websites are automatically blocked by some institutions like banks, libraries and most schools for security and privacy reasons.
Schools are blocking websites to keep children safe within the walls of their establishment. Many social websites are blocked such as Facebook and YouTube. These sites can obtain very inappropriate subjects for children.
There is probably an internet block on your computer which is blocking websites that are not appropriate for children. WikiAnswers however can not tell you how to get past this block, contact your administrator to unblock these websites for you.
General - Restrictions - Disable Restrictions. If you are speaking of websites that are not showing stuff, have a look at them on a desktop computer. Websites with Flash games or animations will not play on the iPad or iPhone.
Pop-Ups on computers can be caused by individual websites or viruses on your computer. To block them, download a computer Anti-Virus & Protection Program that enables pop-up blocking.
Each school has different kinds of blocking with websites.
You may be using a browser which the sites don't support. Try using a different browser. If the problem still persists, then maybe there is a blocking system on the computer which is censoring the sites.
The test that can prove which computer's firewall is blocking a program from running is to turn off the firewall on the computer being used, then try to run the program in question. If the program still doesn't work, then the main computer is blocking the program.
The test that can prove which computer's firewall is blocking a program from running is to turn off the firewall on the computer being used, then try to run the program in question. If the program still doesn't work, then the main computer is blocking the program.
Contact your system administrator. They will have access to the website blocking list and can add or remove websites as needed.
There are many programs and tools on the computer that can cause website to be blocked. Unless your computer is detecting a bad virus, it is not likely that the anti-virus software is not doing the blocking. Windows has but in security features that allow you to change the level is security protection being used. Firewalls also block websites based on what it is set to allow and disallow.
A computer virus, probably.
Your computer may be blocking the Captcha site. If you continue to have issues with it and your computer is not blocking it, contact Support or post on the Community Forum under Malfunction Discussion.