Open Firefox.
   Click on the menu button (three horizontal lines) in the upper right corner.
   Select Settings (or Options).
   In the left sidebar, click on Search.
   Under the "Default Search Engine" section, select your preferred search engine from the dropdown menu (e.g., Google, DuckDuckGo, etc.).

   Open Firefox.
   Click on the menu button and select Settings.
   In the left sidebar, click on Home.
   Under the "Homepage and new windows" section, make sure the homepage is set to your preferred website. You can choose "Firefox Home" or enter a custom URL.

   Click on the menu button and go to Add-ons and Themes.
   In the Extensions tab, look for any suspicious or unfamiliar extensions that may be causing the issue.
   Disable or remove any extensions that you do not recognize or trust.

   Click on the menu button and go to Help.
   Select More Troubleshooting Information.
   Click on the Refresh Firefox button. This will restore Firefox to its default state while saving your essential information like bookmarks and passwords.

   Run a full system scan using your antivirus software to check for any malicious software.
   Consider using a dedicated malware removal tool, such as Malwarebytes Malwarebytes, to scan your system.

'''1. Change Your Default Search Engine''' To change your default search engine in Firefox: Open Firefox. Click on the menu button (three horizontal lines) in the upper right corner. Select Settings (or Options). In the left sidebar, click on Search. Under the "Default Search Engine" section, select your preferred search engine from the dropdown menu (e.g., Google, DuckDuckGo, etc.). '''2. Check Your Homepage Settings''' To change your homepage settings: Open Firefox. Click on the menu button and select Settings. In the left sidebar, click on Home. Under the "Homepage and new windows" section, make sure the homepage is set to your preferred website. You can choose "Firefox Home" or enter a custom URL. '''3. Check for Extensions''' Sometimes, browser extensions can change your search engine or homepage: Click on the menu button and go to Add-ons and Themes. In the Extensions tab, look for any suspicious or unfamiliar extensions that may be causing the issue. Disable or remove any extensions that you do not recognize or trust. '''4. Reset Firefox Settings''' If the above steps do not resolve the issue, you can reset Firefox to its default settings: Click on the menu button and go to Help. Select More Troubleshooting Information. Click on the Refresh Firefox button. This will restore Firefox to its default state while saving your essential information like bookmarks and passwords. '''5. Check for Malware''' If Bing keeps appearing despite your changes, it may be due to malware or adware: Run a full system scan using your antivirus software to check for any malicious software. Consider using a dedicated malware removal tool, such as [https://www.malwarebytes.com/mwb-download Malwarebytes] Malwarebytes, to scan your system.