Install CC Cleaner. Its free and a very good tool. Run it to clean Temp. Internet files, cookies, clipboards, memory dump etc. Use it to uninstall unnecessary programs. Use Startup function to see which processes load on startup. E.g Yahoo Messanger, Unnecessary toolbar, Webcam, Bluetooth etc are not required when you start the pc and hog memory and slowdown the system. These can safely be disabled.
I killed all process some disabled and others are SYSTEM process which automatically start after kill. in safe mode cpu usage is 10% but I cannot connected to net and screen become very zoom