Restart the computer
Close unused programs
Disable startup apps
Uninstall unused software
Delete temporary files
Clear browser cache
Update the operating system
Update drivers
Scan for malware
Free up disk space
Defragment a hard drive if using one
Upgrade to an SSD
Add more RAM
Reduce browser tabs
Lower visual effects
Check for overheating
Clean dust from vents and fans
Use a lighter antivirus
Keep software updated
Reinstall the operating system if needed