Defragging a computer can help improve performance by reorganizing fragmented data on your hard drive. On Windows, you can use the built-in "Defragment and Optimize Drives" tool. Simply search for it in the Start menu, select your drive, and click "Optimize." It's important to note that SSDs don't need defragging. Have you noticed your computer slowing down recently? Let me know if there's anything else I can assist you with!