My kernel task is using 400% of my CPU

Question

My coMputer is very slow, i need help. I saw the kernel task and  is using yhe 400% of my CPU.
Hardware Information:
          MacBook Pro (13-inch, Mid 2012)
          MacBook Pro - model: MacBookPro9,2
          1 2.5 GHz Intel Core i5 CPU: 2 cores
          4 GB RAM
Video Information:
          Intel HD Graphics 4000 - VRAM: 1024 MB
System Software:
          OS X 10.9.2 (13C64) - Uptime: 0 days 0:5:35
Disk Information:
          APPLE HDD HTS547550A9E384 disk0 : (500.11 GB)
                    EFI (disk0s1) <not mounted>: 209.7 MB
                    MacBokk Pro CJ4LV4R3z (disk0s2) / [Startup]: 499.25 GB (473.36 GB free)
                    Recovery HD (disk0s3) <not mounted>: 650 MB
          MATSHITADVD-R   UJ-8A8 
USB Information:
          Apple Computer, Inc. IR Receiver
          Apple Inc. BRCM20702 Hub
                    Apple Inc. Bluetooth USB Host Controller
          Apple Inc. Apple Internal Keyboard / Trackpad
          Apple Inc. FaceTime HD Camera (Built-in)
FireWire Information:
Thunderbolt Information:
          Apple Inc. thunderbolt_bus
Launch Daemons:
          [System] com.adobe.fpsaud.plist 3rd-Party support link
User Login Items:
          iTunesHelper
Internet Plug-ins:
          FlashPlayer-10.6: Version: 12.0.0.77 - SDK 10.6 3rd-Party support link
          Flash Player: Version: 12.0.0.77 - SDK 10.6 3rd-Party support link
          QuickTime Plugin: Version: 7.7.3
          Default Browser: Version: 537 - SDK 10.9
Audio Plug-ins:
          BluetoothAudioPlugIn: Version: 1.0 - SDK 10.9
          AirPlay: Version: 2.0 - SDK 10.9
          AppleAVBAudio: Version: 203.2 - SDK 10.9
          iSightAudio: Version: 7.7.3 - SDK 10.9
iTunes Plug-ins:
          Quartz Composer Visualizer: Version: 1.4 - SDK 10.9
3rd Party Preference Panes:
          Flash Player  3rd-Party support link
Old Applications:
          None
Time Machine:
          Time Machine not configured!
Top Processes by CPU:
              18%          com.apple.WebKit.Networking
              13%          syncdefaultsd
               7%          WindowServer
               5%          com.apple.WebKit.WebContent
               4%          mdworker
Top Processes by Memory:
          98 MB          Safari
          94 MB          com.apple.WebKit.WebContent
          33 MB          Dock
          33 MB          WindowServer
          29 MB          EtreCheck
Virtual Memory Information:
          2.47 GB          Free RAM
          890 MB          Active RAM
          130 MB          Inactive RAM
          543 MB          Wired RAM
          191 MB          Page-ins
          0 B          Page-outs

Answer 1

The kernel is using excessive processor cycles. Below are some possible causes for the condition.
Throttling
When it gets high temperature readings from the hardware, or a low-voltage reading from the battery, the kernel may try to compensate by interrupting the processor(s) to slow them down and reduce power consumption. This condition can be due to
a buildup of dust on the logic board
high ambient temperature
a worn-out or faulty battery in a portable
the malfunction of a cooling fan, a temperature sensor, a voltage sensor, or some other internal component
Note that if the problem is caused by a sensor, there may be no actual overheating or undervoltage.
If the computer is portable, test with and without the AC adapter connected. If kernel_task hogs the processor only on battery power, the fault is in the battery or the logic board. If it happens only on AC power, charging is causing the machine to heat up. That may be normal on some models. CPU usage should drop when charging is complete.
Apple Diagnostics or the Apple Hardware Test, though not very reliable, is sometimes able to detect a fault. For more thorough hardware testing, make a "Genius" appointment at an Apple Store, or go to another authorized service provider.
If nothing is wrong with the hardware, then whatever you can do to improve cooling may help.
Installed software
User-installed software that includes a device driver or other kernel code may thrash the kernel. That category includes virtualization software, such as Parallels and VMware, as well as most commercial "anti-virus" products. Some system-monitoring applications, such as "iStat," can also contribute to the problem. You can test for this possibility by completely disabling or removing the software according to the developer's instructions, or starting in safe mode. Note, however, that disabling a system modification without removing it or testing in safe mode may not be as easy as you think.
Corrupt NVRAM or SMC data
Sometimes the problem is cleared up by resetting the NVRAM or the SMC.
External display
Connecting an external LCD display to some MacBook Pro models may cause this issue. If applicable, test by disconnecting the display. You might get better results with a newer LED display.