Reboot your computer
Most people know that rebooting can fix computer problems. What you may not know is that turning off the power by shutting down (called a cold boot) does a better job than simply using the restart command (a warm boot). If you hibernate your computer, you should give it a reboot now and then to clear any sleep-related snafus.
Scan for viruses and malware
Your next troubleshooting step should be to scan for viruses and malware using your usual antivirus program. Remember, some viruses can sneak past your computer’s defenses, which is why it’s important to watch what you click. Preventing viruses is easier than trying to remove them.
Run a cleanup utility
Cleanup utilities take care of little problems before they become big ones. Two of my favorites are CCleaner for Windows and Sierra Cache Cleaner for Mac. Watch out for computer viruses masquerading as cleaning utilities.
Reboot your network
If other devices are also slow, your network may be the culprit. Try rebooting by turning your router and/or modem off, then on again.
Install software updates
Updates fix bugs that can cause computers to slow down or crash. Keeping your computer updated helps to avoid these software bugs and keeps your computer more secure.
Quit apps when not in use
You should always quit apps when you’re not using them. Many people simply click out of the active window but leave the app running, which uses up extra memory and slows down your computer.
Add more memory
You may be able to add more memory to your computer. Check your manufacturer’s web site for configuration options.