Using An HTTP Proxy Within A Browser

Instead of using a proxy website you can integrate a proxy server into your browser. It is somewhat simpler once you get it to work, but, like any method, it might not work, and you might need to have a separate browser installed.
If you can get into the options of the browser on the blocked computer, it's a very simple process. In Firefox, click "Tools", "Options". Under the "General" tab, click "Connection Settings...".
Select "Manual Proxy Configuration", and in the "HTTP Proxy:" box enter the IP address of the proxy you're going to use. In the "Port:" box, enter the port number.
See the screenshot below:

Typically, when you see an IP address, it will be in IP:port format. This means that when you see a string of numbers, it will have the IP address, then a colon, and then the port number.
One way to use a proxy in Firefox is to use the "Finding And Using Anonymous Proxies" hack from www.i-hacked.com.
You can find this hack HERE, or see the version i have hosted on Project BlockerBuster HERE.

Concerning Internet Explorer, to access the proxy settings, click "Tools", then "Internet Options". Under the "Connections" tab, click "LAN Settings". In the dialog box that comes up will be the proxy settings.
See the screenshot:

An HTTP Proxy works the same way as a circumventor website, except it is integrated into your browser so that you do not have to fill out a form.
It will still be slow like before, and the blocking software might or might not allow it.
The blocker software itself might be configured as a proxy in the browser, in which case getting past it might be as simple as removing the proxy address from browser settings, but typically that could cause a loss of all access to the internet.