It appears that your computer is infected with Malware or Adware, which can display unwanted ads on your desktop wallpaper and web browser. To remove these ads and regain control of your computer, please follow these steps:

1. Update your computer’s operating system and antivirus program. This will ensure that your computer’s security patches are up to date and the latest virus definitions are downloading.
2. Run a full scan. Most antivirus programs provide the option to scan my computer. Select this and wait for the scan to complete.
3. Remove any malicious programs that were found. If any suspicious or unwanted programs were detected during the scan, click remove and follow the steps to delete them from your computer.
4. Contact a professional. If your antivirus scan did not identify the malicious programs, it is recommended that you contact a computer security professional to assess your computer.