Here are some common troubleshooting solutions that can drastically improve overall computer performance.
Manage startup programs
Some programs start themselves automatically when you start Windows. Too many of these programs opening at the same time can slow down your computer. To disable these programs from startup and improve performance, use Windows Defender. For more information, see this article from Microsoft.
Open Disk Cleanup
This tool deletes unnecessary or temporary files on your hard disk so you can increase the amount of storage space you have.
Reduce the number of open programs or windows
If you notice erratic or reduced performance on your computer, you might be trying to run too many programs at the same time. This can cause display problems such as jittery or choppy video. The more programs you have open on your desktop, the more system resources Windows needs. Try closing programs that you are not currently using, or reducing the window size.
Avoid running too many graphics-intensive programs at the same time
Even if you have only a few programs running, some programs (such as video-editing programs) and features (such as high-definition video streaming) use a lot of system resources. Running too many of these programs at the same time puts strain on system resources and might degrade display quality or make video appear jittery or disconnected.
Restarting can fix mysterious performance problems when the exact cause is hard to pinpoint. Restarting a PC is a good way to clear out its memory and ensure that any errant processes and services that started running get shut down.
Reduce your monitor's resolution
On some computers, very high resolutions require a lot of system resources to display properly. If you notice problems at high resolutions, try lowering the resolution until the problems disappear. To do this, open the Display Options window in Windows. Under Resolution, move the slider to the resolution you want, and then click Apply.
Upgrade to a more powerful video card
A computer's video card contains dedicated memory that it uses to display graphics. The more memory the card has, the better the quality. If your card does not display the way you would like it to, consider upgrading to a faster video card.
Access advanced system tools such as Event Viewer, Disk Defragmenter, and System Information, that system administrators and IT professionals often use to solve problems. You can also view notifications about performance-related issues and what to do about them. For example, if Windows detects that a driver is reducing performance, click the notification to learn which driver is causing the problem and view help on how to update the driver. Issues listed at the beginning of the list are impacting the system more than issues listed later in the list.