Problem of Slow Running Dell Laptop Returns

As I mentioned above, my computer problem returned, yesterday. It's running very slow. When I shut it down, it will flash the "You Need to Force These Programs to Close" twice. However, I've closed all the programs before shutting it down and the area that's supposed to display the programs is blank. It even takes 1~2 seconds for the text that I'm typing to appear on the screen.
So, I repeated the procedure you gave me that fixed this problem 3~4 weeks ago. The thread is...

Problem of Slow Running Dell Laptop Returns