Configure & Use Web Browsers | CompTIA IT Fundamentals FC0-U61 | 3.5

In this video you will learn about configuring & using web browsers by caching & clearing cache, deactivating client-side scripting, configuring browser add-ons & extensions, setting up private browsing, configuring proxy settings, configuring certificates, popup blockers, script blockers and compatible browser applications.

Caching/Clearing Cache

A browser cache (pronounced cash) is a temporary storage area in memory or on disk that holds the most recently downloaded web pages. As you jump from webpage to webpage, caching those pages in memory lets you quickly go back to a page without having to download it from the web again. The browser cache (also known as cached data and files or cached images and files) is one of several items you can clear when you select the option to clear browsing data.  Here’s how to get to the browser cache settings in several popular browsers.

Google Chrome

Click the three-dot menu button, More Tools, Clear browsing data…The Clear browsing data, Basic dialog lets you select the time period to clear and what to clear.  Cached images and files is selected by default.  Click the Advanced tab to choose additional items and see details.  Click Clear Data to clear selected information.

Google Chrome

Microsoft Edge

Click the three-dot menu button, Settings, Choose what to clear (clear browsing data).  Click Clear to clear the selected items.

Microsoft Edge

Mozilla Firefox

Click the three-line menu button, Options, Privacy & Security.  To choose what to clear, click Clear History.  Select the time range to clear.  Click the Details arrow to choose what to clear.  Click Clear Now.

Mozilla Firefox

Microsoft Internet Explorer

Click the gear (settings) icon, then click Safety.  Click Delete Browsing History.  By default, temporary internet and website files, cookies and website data, and history will be deleted.  Favorite website data will be kept. Make any changes desired and then click Delete.

Microsoft Internet Explorer

Deactivate Client-Side Scripting

Browser pages can use two types of scripts.  Server-side (back-end) scripts perform tasks at the server, such as creating dynamic HTML pages.  Client-side scripts are used to process user input and are usually written in JavaScript. Client-side scripts can be a security risk, so browsers have options to deactivate client-side scripts, including settings and add-ons.  The following sections provide details for managing JavaScript settings in leading browsers.

Google Chrome

Open Settings, Advanced Settings, Privacy & Security, Content Settings and then select JavaScript.  You can allow or block JavaScript by specifying websites or you can block all websites from using JavaScript.

Mozilla Firefox

Enter about:config into the navigation window and click I accept the risk to continue.  Search for javascript.enabled.  Right-click the line and select Toggle to turn it off.

Microsoft Edge

Current versions of Windows 10 do not include any built-in options for disabling scripting in Microsoft Edge (the default browser).  However, you can use a script blocker add-on.

Microsoft Internet Explorer

In Internet Explorer, you can set different zones to have different security options.  To start, click the gear icon or open the Tools menu, and the click Internet Options.  Click the Security tab and then click the zone to change, typically the Internet zone.  Click Custom level.  To change scripting settings, scroll down to the Scripting section and select Active scripting.  Click Disable to disable all scripting.  To enable all scripting, click Enable.  To be prompted when a page has a script, click Prompt.  Click OK, then OK again on the next dialog to close the window.

Browser Add-Ons/Extensions

Browser add-ons and extensions enable users to customize a browser’s features and add additional options.  Browser add-ons and extensions can be used to disable potentially dangerous scripts. Exactly what you can do with your browser with extensions varies, but there are plenty of options.


To add an extension, open a web browser and navigate to its extension website.  Search for or browse to locate the extension you want and then click it. With Chrome, click + ADD TO CHROME to install; then follow the prompts to finish the process.  With Firefox, click +Add to Firefox to install.  With Microsoft Edge, click Get the app to install.  With Internet Explorer, click Add and then follow the prompts to finish the process.


After you install an extension, you may need to enable it before you can use it.  Google Chrome enables extensions automatically. If you need to disable an extension, click the three-dot menu button, click More tools, Extensions, and then slide its control to the left.  To enable a disabled extension, slide its control to the right. Mozilla Firefox also enables extensions automatically.  If you need to disable an extension, click the three-line menu button, click Add-ons, and click its Disable button.  To enable a disabled extension, click Enable. Microsoft Edge does not enable newly installed extensions automatically.  After you install an extension, Edge prompts you to turn it on or keep it off.  To disable an installed extension, click the three-dot menu button, click Extensions, click the extension, and slide the control to Off. To manage installed extensions in Internet Explorer, click the gear (Settings) button or open the Tools menu and click Manage add-ons.  Currently loaded toolbars and extensions are shown first.  To see all add-ons, select the option from the Show menu at the lower left.  To enable a disabled extension, click it, then right-click it and choose Enable.  To disable an enabled extension, click it, then right-click it and choose Disable.


If you decide a particular extension isn’t what you want to use, you can remove it.  To remove an extension in Google Chrome or Mozilla Firefox, open the extension dialog and click the extension’s Remove button.  To remove an extension in Microsoft Edge, open the extension dialog, click the extension to remove, and click Uninstall.  To remove an extension in Internet Explorer, double-click it and click Remove from the More information dialog.  If the Remove option is not available, use the Add/Remove Programs dialog in Control Panel to uninstall it.  You might need to close and restart your browser to complete the process.  With some browsers, you must enable an extension before you can remove or uninstall it.

Private Browsing

A private browser allows you to use a shared computer or someone else’s device while preventing your passwords, search records, and browsing history from being saved on that device. However, private browsing does not prevent your activity from being visible to corporate monitoring (if you use a corporate computer) or your internet service provider.  Downloads and bookmarks will be saved.

Google Chrome Incognito Mode

In Google Chrome, this feature is called Incognito.  Click the three-dot menu button and select New incognito window to start.  In Mozilla Firefox, start Private Browsing by clicking the three-line menu button and selecting New Private Window.  In Microsoft Edge, click the three-dot menu button and click New InPrivate Window.  With Internet Explorer, open the Safety menu or click the gear (menu) button and select Safety, then click InPrivate Browsing.

Microsoft Internet Explorere InPrivate Browsing

When you are finished with private browsing, close all private browsing windows and tabs.

Proxy Settings

A proxy server is a dedicated computer or a software system on a local network that acts as an intermediary between a single computer user and the internet so that the network can ensure security, administrative control, and caching service.  The proxy server may exist in the same machine as a firewall server or it may be on a separate server, which forwards requests through the firewall. If a web browser on the network requests a page, the proxy server checks to see if an updated copy of the page is already in its web page storage.  If it is, the proxy server’s copy of the web page is sent as a response. If not, the proxy server updates its copy and then sends an updated copy.

Web browsers must be configured to use proxy servers.  Many networks provide a proxy script at login to make these settings for network users.  There are typically four proxy settings that can be used.  Depending on the network, all proxy servers might use the same setting or might use different settings:

  • HTTP proxy:  Used for web browsers.
  • SSL proxy:  Used for Secure Sockets Layer (SSL) encrypted web traffic.
  • FTP proxy:  Used for File Transfer Protocol.
  • SOCKS Host:  Used for socket secure connections for exchanging network packets.  The user may be prompted to select the version of SOCKS Host to use.


A website security certificate is a validation and encryption tool, part of the HTTPS protocl, which secures and encrypts data going back and forth between the server and the client browser. It is issued by a trusted certification authority (CA) who verifies the identity of the owner of a website. The certificate then ensures the user that the website it is connected to is legitimate and that the connection is safe and secure.

Website Security Certificate


A valid certificate is a certificate that is issued by a recognized certificate authority for the company that owns the website and has a current date range.

Valid Certificate


An invalid certificate has one or more of the problems:

  • Expired: Certificates are good for a specified date range. If you visit a secure website after the date range on the certificate, the certificate is expired.
  • Wrong Host: The certificate being used by a website does not match the name of the owner. This can indicate the certificate is being used fraudulently.
  • Self-Signed: Website used a self-signed certificate, not a certificate from a certificate authority.
  • Untrusted Root Certificate: The issuer certificate is unknown.
  • Revoked: Certificate revoked by certificate authority.

Pop-Up Blockers

A pop-up blocker is any program that prohibits a pop-up at some point in time. This may consist of multiple internet windows, or actual pop-ups caused by coding on a webpage. Generally, pop-up blockers are installed to avoid pop-up ads from webpages. Most browser software allows the user to turn the blocker on or off. Pop-ups have been used for advertisements as well as fake virus infection scares, but they are sometimes used for mapping and other desirable content.  When a website displays a pop-up, the user is prompted to decide what to do. If you choose the option to allow pop-ups from a particular website, you can view and manage the list of allowed websites.

Pop-Up Blocker

To manage pop-up settings with Chrome, click the Manage button or open settings/content/popups.  To manage pop-ups with Firefox, click the Edit Pop-up Blocker Options or open the Preferences:  Privacy & Security menu.  To manage pop-ups with Microsoft Edge, you must use the Windows Registry Editor.

Script Blockers

Google Chrome offers extensions such as ScriptSafe and Script Blocker. These and others are available from the Chrome Web Store. Firefox can use add-ons such as NoScript Security Suite and uBlock Origin.  These and others are available from the Firefox Add-ons website. The Microsoft Store’s Extensions for Microsoft Edge website includes several ad blockers and the script manager uBlock Origin.

Compatible Browser for Application(s)

If you are unable to use your browser with a particular website, check the following:

  • Check your browser version against the website’s list of approved browsers.
  • Make sure you are using the latest version of the browser.
  • Turn off any script blocker software.

Caution:  A “WARNING”:  Your current browser is Outdated!” message and clickable link can be used to trick users into installing malware.  If you need to update your browser, visit the browser vendor’s official download website. Don’t click a link; instead, close the browser window.

Some applications that work with browsers will work only with certain browser versions.  Internet Explorer includes a Compatibility View setting that can be used to enable it to display pages that were designed for older versions of IE.