Teste isso:
Abra um terminal.
Pressione Ctrl + Alt + T
Execute:
sudo -i
apt-get clean
apt-get autoremove
UNUSCONF=$(dpkg -l|grep "^rc"|awk '{print $2}')
apt-get remove --purge $UNUSCONF
NEWKERNEL=$(uname -r|sed 's/-*[a-z]//g'|sed 's/-386//g')
ADDKERNEL="linux-(image|headers|ubuntu-modules|restricted-modules)"
METAKERNEL="linux-(image|headers|restricted-modules)-(generic|i386|server|common|rt|xen)"
UNUSKERNELS=$(dpkg -l|awk '{print $2}'|grep -E $ADDKERNEL |grep -vE $METAKERNEL|grep -v $NEWKERNEL)
apt-get remove --purge $UNUSKERNELS
apt-get install --reinstall deborphan
deborphan
apt-get --purge remove $(deborphan)
deborphan --libdevel
apt-get --purge remove $(deborphan --libdevel)
deborphan --find-config
dpkg --purge $(deborphan --find-config)
apt-get update
apt-get dist-upgrade
dpkg --configure -a
apt-get -f install
apt-get clean
reboot