Speed up a slow Windows PC (free, 15 minutes)

Try these before buying anything.

1. Restart it. Properly: Start, Power, Restart. "Shut down" on Windows often only hibernates.
2. Startup apps. Press Ctrl+Shift+Esc, open Startup apps, and disable everything you don't need running from the moment you log in.
3. Free up space. Settings, System, Storage, then Temporary files. Keep at least 15% of the drive free.
4. Uninstall what you don't use. Settings, Apps. Trial antivirus and "PC cleaner" tools are common slowdowns.
5. Check for updates, including Windows Update's optional driver updates.
6. Look at Task Manager while it feels slow. Sort by CPU, Memory and Disk. Whatever is at the top is your culprit.
7. Browser tabs use a lot of memory. Twenty open tabs can be the whole problem.

If the disk is still at 100% most of the time, the computer probably has an old hard drive. Swapping it for an SSD is the single biggest upgrade for an older PC.