Few easy things to try first. Turn off Automatic Updates. Clean out all temp files and clean registry - Glary Utilities will do this well.
http://www.glaryutilities.com/
Reboot, turn on automatic updates. Let us know if it is still giving you problems with the updates.
Then, do Ctrl-Alt-Del, go to Task Manager. Look at what process is running and eating up your CPU cycles. Let us know.
Also, some details on your PC would be good, like what OS you are running...
TC