Win XP Home updates & pwr off problem

I am currently haveing problems with my WinXP Home. I am unable to run windows updates, IE basically locks up evertime I try to access the updates. I am able to access any other site I have tried to goto. Even if I open the browser and manually try same thing. I also have problems shutting down the pc, it hangs after I do start, shutdown requiring me to press the power button. This is a computer less than 6 monthes old.