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http://www.bitdefender.de/media/html/de/pcwelt/

Do not worry as the interface is in German language, but anyways enter your details!
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Download BitDefender Internet Security 2011 from the following options:
Online Installer: http://download.bitdefender.com/windows/installer/en-us/bitdefender_isecurity.exe
32bit Offline Installer: http://download.bitdefender.com/windows/desktop/i_security/2012/en-us/bitdefender_is_2012_32b.exe
64bit Offline Installer: http://download.bitdefender.com/windows/desktop/i_security/2012/en-us/bitdefender_is_2012_64b.exe
Install and use your key!