The Avast anti virus program now includes a software updater module that keeps track of the latest versions of the various web browsers as well as a few other programs such as Adobe Reader so as to automatically keep those programs up to date for you (and so hopefully prevent security holes that have been discovered in the prior version from being exploited on your computer). Since such updates can generally only be done through an administrator account the options for configuring the Software Updater include being able to disable the automatic update and also to only report when programs need updating when you are logged in as administrator (which you should only do when running maintenance on your system (and so resulting in your probably never seeing the messages about the updates).
A far superior alternative to this new Avast Software Updater is the program from Secunia that doesn't just monitor a handful of programs on your system but which monitors hundreds of different programs on your system, updates automatically those that can be updated without administrator intervention and which tells you about those that it can't update automatically so that you can run the Secunia program as administrator from your regular user account to handle most of the remaining updates.
With Secunia installed the Avast Software Updater is just taking up resources on the computer unnecessarily as Secunia will automatically update most of the programs that Avast tells you about without requiring you to log in to your administrator login in order to do so. Unfortunately the people who wrote the Avast Installer didn't provide an option there so that you can leave the Software Updater out when you install Avast.
The Software Updater is a separate module that is in fact installed separately, it is just the option to not install it in the first place that is missing (if you are upgrading from a prior version of Avast - apparently it is selectable if you are doing a brand new custom install). It is therefore possible to uninstall the Software Updater without affecting the Avast anti-virus module.
To uninstall the Avast Software Updater you must first login as administrator (as you usually have to in order to uninstall programs). If you then go into the windows Control Panel and select "Add or Remove Programs" (if you are running XP) or "Programs" then "Uninstall a program" (if running Windows 7). Scroll down until you find the entry for Avast Anti-Virus and then select the Change button.
In the program that now runs you will see a Component tab and when you select that you will see a list of the available components that Avast now has with a checkbox next to each. For the currently installed components the checkbox will be checked. Simply uncheck the checkbox for the Software Updater and that option will be uninstalled.