Restart the PC regularly
Close unused background apps
Disable startup programs
Uninstall unnecessary software
Update Windows or macOS
Update device drivers
Run antivirus and malware scans
Free up disk space
Delete temporary files
Use an SSD instead of an HDD
Add more RAM
Lower visual effects and animations
Set power mode to High Performance
Keep the PC cool and dust-free
Check for overheating
Defragment HDDs only
Keep browser tabs and extensions minimal
Update BIOS or firmware if needed
Reinstall the operating system if performance is still poor