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Windows Automatic Update Service (WAUS) FAQ
(formerly Software Update Service - SUS)

  • What is WAUS?
    • - WAUS stands for Windows Automatic Update Service. This is a service provided by Penn's division of Information Systems and Computing (ISC) to keep your computer's Windows operating system up-to-date with the latest critical updates. These updates are necessary to help keep your computer and your data secure.
  • Why is it important to keep my computer up-to-date with security patches?
    • - Though operating systems are designed to be secure, sometimes they still contain vulnerabilities. If you don't keep your computer up-to-date, then you run a high risk of having your computer compromised (hacked). Hackers may be interested in your personal data, or in using your computer for attacks on other computers. If that happens, you may be disconnected from PennNet.
  • What operating system do I need to use this service?
    • - In order to participate in the WAUS service, you need to be running Windows XP Service Pack 3 or Windows Vista Home Premium, Business, Ultimate or Enterprise with Service Pack 1.

  • I use a Macintosh computer. Can I use WAUS?
    • - No. WAUS is for computers running Windows OS only. You can keep your Macintosh up-to-date by using Software Update located under the Apple Menu.

  • How do I know what Windows operating system I am running?
    • - The easiest way to find out is to right-click on the My Computer icon to bring up a contextual menu. Click Properties at the bottom of the menu. In the window that appears, you will see your operating system version listed after "System".

      - If your computer doesn't have an icon for "My Computer" on the desktop, locate "My Computer" in the Start menu. Right mouse click on "My Computer" and select "Properties" from the menu that appears. You will see your operating system version listed under "System".

  • Besides my Windows operating system, does WAUS patch anything else?
    • - WAUS will patch vulnerabilities in Internet Explorer as well as your Windows operating system. No other applications are patched by this service (not Microsoft Office, antivirus software, or other browsers, etc.).

  • What are service packs and does WAUS install them?
    • - Service packs are large, complex updates that are released occasionally which significantly change the inner-workings of your operating system. WAUS does not install service packs. Please check with your ITA or LSP for advice about specific Service Pack installation.

  • How does WAUS know what to install on my computer?
    • - When configured to use WAUS, on a daily basis your computer asks the WAUS server what patches are available. It then checks that list against an inventory of system patches already installed on your computer. Your computer will then download and install the ones you do not currently have installed.

  • Will the University collect and retain information about what is installed on my computer?
    • - No. WAUS is in place purely for your protection and does not retain any information about what software you are using, what your email says, what web sites you visit, or what the content of your hard drive is.
  • Will Microsoft be notified about what software is running on my computer?
    • - No. Since WAUS is running on a local Penn server, your computer does not interact directly with Microsoft while using WAUS.

  • When are WAUS updates available?
    • -The WAUS server will check with Microsoft daily for new patches. New patches will be available through WAUS within two days of Microsoft's release.

  • When will updates be downloaded and installed?
    • - Daily. When your computer is turned on and connected to the internet, it will periodically visit the WAUS server to check and see if there are new patches to download. If new patches are available, your computer will attempt to download them while you are online, to ensure that they are completely downloaded prior to the scheduled 8 PM install time.
      - Patches will be installed on 8 PM of the day that new patches were downloaded.

  • What happens if my computer is turned off during the scheduled installation time (8 PM)?
    • -The new patches will be installed within 5 minutes of turning your computer back on.

  • I've noticed that updates were downloaded, and now Windows is prompting me to install them. Wasn't this supposed to happen automatically?
    • - The WAUS service will install them automatically, but not until 8 PM. If you would like to manually install them earlier in the day, all the better. Just follow the on-screen instructions. Some updates require that you reboot your computer to complete the installation. While it is not necessary to reboot your computer immediately, it is imperative that you restart your computer within 24 hours. Otherwise, WAUS will not completely finish installing the critical patches and your computer will remain vulnerable. In addition, WAUS will cease to obtain additional patches for your operating system until you reboot.

  • I followed the prompts and installed the updates manually. Will this interfere with WAUS?
    • - No. The only way it would interfere with WAUS is if you were prompted to reboot your computer after manual installation and chose not to restart.

  • I ran Windows Update by visiting Will this interfere with WAUS?
    • - No. The only way it would interfere with WAUS is if you were prompted to reboot your computer after installing new patches and chose not to restart.

  • Do I need to reboot my computer once updates are installed?
    • - Some installations require reboots; others do not. You will be prompted to reboot your computer if required. If one is required, it is imperative to follow the instructions. Your computer will not be able to download future patches until it is restarted.

  • I was prompted to reboot my computer and declined, is this a problem?
    • -Although it is not necessary to reboot your computer immediately when prompted, it is imperative to restart your computer within 24 hours. Otherwise, WAUS will not completely finish installing the critical patches and your computer will remain vulnerable. In addition, WAUS will cease to obtain additional patches for your operating system until you reboot.

  • Will I be notified when my computer is downloading new patches?
    • -No. WAUS downloads all the patches in the background. You should not notice the download process.

  • What happens if I unknowingly shut down my computer while it is downloading patches?
    • -Downloading will resume when you restart your computer.

  • Will downloading patches affect my computers performance?
    • -There should be no impact on your computer's performance when patches are being downloaded. The WAUS service will monitor your computer's usage, and adjust the download based on what you are doing at the time.

  • I have WAUS installed, but it doesn't seem to be working. What should I check?
    • - If your computer's clock, in the lower right hand corner of your Task Bar, is not correctly set, this may affect WAUS's functionality. Make sure that your computer's clock is in sync with Penn's timeserver. Instructions are available here.
  • Do I need to have administrative rights in order to use WAUS?
    • -No, this is not necessary to use WAUS.

  • I am going to be taking my computer home for break. Will WAUS work from off campus?
    • - As long as you have a network connection, WAUS will continue to function.

  • I am no longer a student at Penn, may I continue to use WAUS?
    • - No. You must uninstall WAUS if you are no longer affiliated with the University.

  • How do I uninstall WAUS?
    • - It is important that your computer has the latest critical updates installed. If not, you run the risk of being disconnected from PennNet. However if you need to remove WAUS, you can either use the uninstaller in the Programs menu (Start-->All Programs-->Windows Automatic Update Service-->Uninstall Windows Automatic Update Service) or you can follow the instructions below:

      1. Click Start and then click Control Panel

      2. Click Add or Remove Programs.

      3. Click Windows Automatic Update Service, and then click Change/Remove.


    Information Systems and Computing
    University of Pennsylvania
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