Why us ny CPU usage so high?

[MidnightDemon554]

My CPU usage usually spikes from 20%, then goes directly to 100% and causes MASSIVE lag for about 2-5 minutes. Then it will stop for about 10, then spike back up to 100% for 2 minutes. I have three programs running properly, Skype, Google Chrome, and Spotify. Whenever I play a game, lets say, World of Tanks, it would keep spiking to 100%. I've already checked my Computer for Malware, spyware, viruses, etc. etc. But my computer continues to spike. I've closed all programs in order to play my games, but yet it still spikes. I've observed the processes, and it seems that google chrome and my game are the culprits. This is really fustrating considering the fact that my PC ran perfectly before hand, now suddenly this is happening. I really want help as soon as possible. I can't play my games that I paid for. Please respond soon. Thank you.

PC specs:

4.00 GB of RAM
Intel® core™ 2 duo CPU 3.00 GHz
I don't remember my graphics card, but it is enough to run my games on very high resolution.

[Joshua]

You can try to disable some programs and services at startup. To do this, Hold down Windows Key + R and then type "msconfig"(no quotes). Click the "Selective Startup" tick box then go to the Services tab. Tick the "Hide all Microsoft Services." Now disable everything you don't need there(I personally disable everything except for maybe Office and Steam). I would disable stuff like Skype Updater and everything that's from Google. Now go to the Startup tab. Disable EVERYTHING here. Once you have done that, press OK. It will ask you to reboot, do so. I also recommend you do some other maintenance tasks like Disk Cleanup(I prefer Piriform's CCleaner http://www.piriform.com/defraggler better than the default Windows one). I also recommend Malwarebytes for malware, virus scans and its free. On CCleaner, have everything selected EXCEPT Wipe Free Disk Space then click, "Run Cleaner." Then go to the Registry tab, have everything selected and press :Fix Selected Issues." I hope this helped.

[Sujuk]

Joshua has a good answer. Windows is a very inefficient OS; many random things will run in the background on and off. I would check the processes running and see if anything really heavy is going on, then terminate it. If it comes back later then it could be a phase of Windows, where it will happen for some time and then just stop happening. Usually though, these things happen for a little while after a boot-up and then die down.