Is strong recommended to keep updated any antivirus program with latest definitions. malware and exploits are appearing every day, the rate of propagation is huge since Internet is used at a large scale. Avira engineers are working each day to find solutions of new viruses and you MUST update this software often to be ensured you are using PC in a safe environment.
Probably you have downloaded already the main installation file of Avira Free Antivirus ( if not you can find it here ). After installation, you can copy this VDF Update file on your hard disk and choose from the program's interface option "Update Manually". Select this file and your software is up to date!
Is working for - Avira AntiVir Personal, Premium and Premium Security Suite (Unix and Windows XP, Vista and Windows 7 32 bit or 64 bit).
See screenshots/images page on our web site to see exactly how it works manual update.
Important note: when you click manual update and program ask you to select the file, pay attention at the name with the file required. vdf_fusebundle.zip and ivdf_fusebundle_nt_en.zip are different (VDF versus IVDF). Download the requested file in order to work.