I see a lot of you are having problems with the automatic updates, getting error Code 646 and having trouble installing KB982331. This is the way I fixed the problem. First of all, you have to download each update manually from the Microsoft Download Center. I would post the link, but I can't add links since I have less than 25 posts on these forums

. Search for each update according to its tag, which usually starts with the letters KB followed by numbers, and download each. After you're done downloading all six updates manually, restart you computer. Go to Windows Update, and if it still tells you to install the updates go ahead and click on install. That should solve the problem for 5 out of the 6 updates.
If KB982331 still doesn't install, you'll have to disconnect from the internet (disable network), and install the update from Windows Update. Follow these steps:
Click on Start button>Control Panel>Network and Internet>Network and Sharing Center>Manage network connections (located on left side column)>Right click Local Area Connection>Disable
After that, Start button>Control Panel>System Maintenance>Windows Update>Install
Finally, re-enable the network by following the first set of steps and select Enable.
Worked for me, good luck.