Avira AntiVir is a popular antivirus program that you can download and use for free.

It is important to keep antivirus programs up to date with the latest virus definitions so that they are able to detect and remove the latest virus threats.

If you have a computer that is not connected to the Internet, its virus definitions are likely out of date.

In this case you may wish to update Avira's virus definitions manually while offline before connecting to the Internet again.

Updating a computer that does not have an Internet connection will require access to a secondary computer that is able to access the Internet to download the latest virus definitions.

Step 1

Go to a secondary computer with an active Internet connection and plug a USB flash drive into an open USB port.

Step 2

Go to Avira's Incremental AntiVirus Update site (see Resources section), click "Download VDF (container VDF)" and save the file to the computer's hard drive.

Step 3

Click "Start," click "Computer" and open the USB flash drive. Drag and drop the downloaded .zip update file into the flash drive window. A copy of the update will be created on the flash drive.

Step 4

Safely remove the USB flash drive and insert it into the computer without an active Internet connection.

Step 5

Open Avira AntiVir (double-click the "Avira" umbrella icon in the system tray), click "Update" and "Manual Update."