Please describe the bug in a few words, for example, "weather applet crashes on logout":

[João Roberto Lamberti]

Terminal: sudo apt-get install -f
Could not exec dpkg!
E: Sub-process /usr/bin/dpkg returned an error code (100)

Terminal: sudo apt-get update
W: Erro GPG: http://packages.medibuntu.org precise InRelease: As assinaturas a seguir não puderam ser verificadas devido à chave pública não estar disponível: NO_PUBKEY 2EBC26B60C5A2783

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1028229/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[João Roberto Lamberti (joaolamberti)]

Tive um problema mas resolvi com a reinstalação do Ubuntu 12.04 LTS 32 bits, segundo a minha pesquisa o problema é quando o software é instalado compartilhado no mesmo computador com o Windows, embora o mesmo tinha anti-vírus o Ubuntu não, portanto tive problema com vírus no meu computador no partilhamento do Ubuntu, segundo informação o Ubuntu ou LInux nesse caso têm que ter anti-vírus instalados.