1. Check disk health first

CrystalDiskInfo — confirm no Caution or Bad status. A failing drive causes system-wide slowness that no software fix can overcome.

2. Check RAM usage

Task Manager → Performance → Memory. If usage is consistently above 85–90% under normal use, more RAM is the correct fix.

3. Kill background processes

Task Manager → Processes. Sort by CPU or Memory. Identify and uninstall bloatware. Windows 10/11 OEM installs often include trial software that runs constantly.

4. Run Disk Cleanup

Search for Disk Cleanup → Run as administrator → Clean up system files. Reclaim space from old Windows Update files, temp files, and thumbnails.

5. Check for malware

Run Malwarebytes full scan. Cryptomining malware is a common cause of a suddenly slow PC with high CPU usage.

6. SSD upgrade

The single most impactful hardware upgrade for a slow PC. HDD → SSD migration typically cuts application load times by 5–10×.