If your computer is slowing down or behaving strangely, there are a few steps you can take to diagnose and possibly remedy the problem:

1. Check for any suspicious programs or processes, and uninstall or disable them if found.
2. Scan your computer for malware or viruses.
3. Check for any outdated drivers or software and update them to the latest versions.
4. Run a disk cleanup to clean up unnecessary files, temporary files, pictures, videos, old logs, etc
5. Delete all recently installed programs (especially those that may have caused the problem).
6. Switch to a lighter, less resource intensive program or browser.
7. Reinstall the operating system, or perform a clean boot of the current version.
8. Reset the BIOS settings and see if that helps.