It may be that your computer is infected with a virus or spyware. Here is a list of steps you can take to get rid of it:

1. Turn on your computer’s firewall
2. Update your antivirus software and run a full scan
3. Install anti-malware software and run a full scan
4. Uninstall software you don’t need
5. Delete temporary files and clear your browser’s cache
6. Disable unnecessary browser extensions
7. Check system performance settings
8. Wisely manage your startup programs
9. Defragment your hard drive

Following these steps should improve the performance of your computer and prevent it from being vulnerable to viruses and malware.