For the past couple of weeks, the Automatic Updates icon stays in my taskbar. When I try to open it and install "Security Update for Microsoft .NET Framework, Version 1.1 Service Pack 1", it begins installing it. Later, it shows the Automatic Updates icon again as if it had never been installed.

I am tired of wuauclt.exe using up my memory; how do I get it to fix this update?

try manual download and then install
http://www.microsoft.com/downloads/details.ASPx?displaylang=en&FamilyID=A8F5654F-088E-40B2-BBDB-A83353618B38

Cudni