My computer is moving really slow?

I recently bought a lenovo K450 series with 12 gb ram and 4700 processor. I downloaded GunZ 2 on steam and unistalled because it was running laggy but forgot to change my computer to turbo mode. So I try reinstalling it and it was moving at like 23 kb per second. So I stop it and open google chrome and everything I typed in the searchbar was loading super slow. No matter what site I launched it tool forever to load and it use to be ultra fast. Can someone tell me what to do?

If a game lags whilst playing online, it is not always the computer that's the problem.

A constant high speed internet connection also helps.

Try pressing Control+Alt+Delete and click on start task manager. Hit the processes tab and take a look and see if there are any programs that are running than you could close. Be careful not to close the wrong ones though, it might shut down your computer.

If that doesn't solve anything, try downloading SmartPCFixer and let it do a free scan on your computer. https://tr.im/

Go onto task manager then onto Processes and see what applications are using a lot of power. End unnecessary background processes with the 'End Process' button. Then go onto the Performance tab and click 'Resource Monitor…" on the bottom. Now find unnecessary applications again and close them.
Make sure you know what the application is! Don't end a process that you don't know what it is.