Update your browser. Ad blockers will work best if you have the latest version of you internet browser installed. Most browsers update automatically, but to double-check for updates, open the browser's About page (usually found in the Help menu).
If you are using Internet Explorer 6 or 7, you will need to upgrade to at least 8 in order to install an adblocker.
Ad blockers are generally more powerful for browsers other than Internet Explorer. Consider installing Chrome or Firefox for more powerful ad protection.
Consider using a fully free web browser, such as one from the list at the Free Software Directory, instead of their proprietary counterparts. These alternatives look and work almost exactly the same with additional focus on privacy features:
IceCat instead of Firefox;
Chromium instead of Google Chrome;
Gnuzilla instead of SeaMonkey
Find an adblock extension. There are adblock extensions for every major browser. These extensions will detect and remove ads from websites. Some extensions will be more effective than others, and removing ads may cause problems with the website you are viewing. Below are some of the more popular extensions for the major browsers. Note that AdBlock and Adblock Plus are different products.
Internet Explorer - Adblock Plus
Chromium (Google Chrome) - AdBlock, Adblock Plus, uBlock
IceCat (Firefox, Iceweasel), Gnuzilla (SeaMonkey) - Adblock Plus, Adblock Edge, uBlock
Safari - AdBlock, Adblock Plus, uBlock
Visit the website. You can download these extensions from your browser's extension manager, but it will be quicker if you install it from the product's website. Visiting the website will automatically provide you the link for your specific browser
Install the extension. The process will vary a little bit depending on the browser, but generally you just need to click the Install or Download button on the ad blocker's website. You will usually be asked to confirm that you want to install the extension.
If you are using Internet Explorer, the setup process will occur much like a regular program.
Restart your browser. In order to complete the installation of your extension, you will need to restart your browser. If you are using Internet Explorer, click the Enable button at the bottom of the window.
Add sites to your whitelist. Many sites rely on advertising revenue to stay online. If you visit a site often, consider adding it to your ad blocker's whitelist. This will allow the website to potentially make revenue off of your visit.
To add a site to the adblocker's whitelist, open the adblocker's configuration page and add sites manually, or visit the site and then use the adblocker's extension button to add the site.