Add more memory
This isn't a guide to buying hardware that will speed up your computer. But no discussion of how to make Windows run faster would be complete without mentioning that you should consider adding more random access memory (RAM) to your PC.
If a computer running Windows 7 seems too slow, it's usually because the PC doesn't have enough RAM. The best way to speed it up is to add more.
Windows 7 can run on a PC with 1 gigabyte (GB) of RAM, but it runs better with 2 GB. For optimal performance, boost that to 3 GB or more.
Another option is to boost the amount of memory by using Windows ReadyBoost. This feature allows you to use the storage space on some removable media devices, such as USB flash drives, to speed up your computer. It’s easier to plug a flash drive into a USB port than to open your PC case and plug memory modules into its motherboard.
Check for viruses and spyware
If your PC is running slowly, it's possible that it's infected with a virus or spyware. This is not as common as the other problems, but it's something to consider. Before you worry too much, check your PC using antispyware and antivirus programs.
A common symptom of a virus is a much slower-than-normal computer performance. Other signs include unexpected messages that pop up on your PC, programs that start automatically, or the sound of your hard disk constantly working.
Spyware is a type of program that's installed, usually without your knowledge, to watch your activity on the Internet. You can check for spyware with Windows Defender or other antispyware programs.
The best way to deal with viruses is to prevent them in the first place. Always run antivirus software and keep it up to date. Even if you take such precautions, however, it's possible for your PC to become infected.