I had the same problem with heat when I first got this laptop. If you go to the Dell support site for this laptop, they have an automated system check and driver update that works wonders. I'll warn you that you will have to hunt a little on the site to find it. I'm afraid that Best Buy won't allow me to send you a link to the page.
After running it, my heat issue was fixed completely; and the laptop runs at a nice ambient temperature now.
I'm not sure why you got an error about something not being compatible with Windows update, but you might want to try running Dell's system check first and then try it again.