Windows Update Errors on my Alienware M11xr2

Hello everyone. I've been having this problem for a few months and Dell has refused to help me with it so I decided to see if anyone on here can help me out before I decide to do something rash like reinstall Windows 7.

Back in June I ran Windows Update and it tried to install an update for Microsoft Silverlight and it said it failed to update giving me error code 64C. When I tried to manually uninstall/reinstall Silverlight, I got the following message:

The feature you are trying to use is on a network resource that is unavailable.

Then the installer quits. But now the problem is also happening with my Zune software when it tries to update and Microsoft Security Client, which about a month ago began to give me messages upon startup that it could not be launched and if the problem persists it should be reinstalled citing error code 0x80070715.

Does anyone have any idea what might be going on here?