If you cannot connect to any websites, the problem is usually caused by the fact that the proxy server currently selected in A4Proxy “as default” is not working. Switch A4Proxy to the Direct Connection mode (Options menu) and try to connect to a website again. If it works, the problem is the current proxy. A4Proxy offers you a lot of proxies and you can pick any one of them by right-clicking on it and selecting “Set As Default” on the local menu that will appear. The option “Use a new proxy on each request” (Proxy Options tab) must be disabled for this to work.
You must check all proxies, sort them by speed (click on the Response Time column header on the Proxy Check tab, so that the proxies with the least response time number (i.e. the faster ones) will be at the top). Then select one of the proxies with a green circle on the left, as described above. If you have difficulty with a particular proxy, select a different one and see if it makes any difference.
If you want to change proxies automatically for each request, you must check the database from time to time and make sure that all good proxies are grouped at the top of the list and the appropriate number of proxies to use is entered in the option “Use {x} proxies from {0} position”.
If you can’t surf in the Direct Connection mode either, it is possible that the Browser Port (Proxy Options tab in A4Proxy) is occupied by some other software. Run Compatibility Test from the Help menu.