If you have Windows 10 most programs will run when you start the computer you can also select them from the Task Manager by pressing Ctrl-Alt-Del. Go to the Startup tab, where you will see the programs that start when Windows starts. With a right click you can change the status of each program to enabled or disabled.

Viruses are quite dangerous and often play an important factor in the performance of our operating system, as they run secretly in the background without taking into account the high consumption they make. To make sure you do not have a virus on your computer, download and install Malwarebytes and scan for it. You can also use Windows Difender, which is great on Windows 10, but you'll be even more secure with Malwarebytes.