Advanced Photon Source

An Office of Science National User Facility

If Your Computer Gets Blocked

What to do if youre computer gets blocked

The APS utilizes automated network monitoring systems to help guard against viruses and other malicious or unauthorized uses of computer networks. If your computer triggers one of the monitoring systems, you will see this message displayed in your browser:

Your computer appears to have a virus or is generating excessive network traffic directed at the APS firewall. Your computer has been blocked, and no longer has access to the Internet. This automated
blocking is necessary to stop the spread of viruses that have occurred on the APS, beamline and visitor networks.

In order to have network access restored for your computer, please perform the following steps:

  • Verify that you have an up-to-date virus scanner installed and enabled.
  • Verify that you have the latest virus signature files installed.
  • Run a full virus scan of your system.
  • If you have an anti-malware program (such as AdAware or Spybot Search and Destroy), run that as well.
  • If you are running an internet phone program such as Skype, it can cause the scanner to indicate a false positive if not properly configured. You should consider shutting such software down until you determine the cause of the problem.

The network block will stay active for three days unless it is cleared by the APS IT group. You can notify APS IT by creating a Help Desk ticket from another computer ( In the ticket, please indicate that your computer has been sanitized and should be reenabled.

For an urgent request, call the APS IT Group support number: 630-252-9700. During off-hours, if you are a non-APS user, contact the on-duty Floor Coordinator who will then contact the appropriate APS IT personnel. If you are an APS employee, you can contact the Main Control Room during off-hours.