每次我输入命令时sudo apt-get update; sudo apt-get upgrade，它都会显示：
(You might want to run 'apt-get -f install' to correct these.
The following packages have unmet dependencies:
libpam-systemd : Depends: systemd (= 229-4ubuntu12) but 229-4ubuntu4 is installed
E: Unmet dependencies. Try using -f.)
然后当我输入时sudo apt-get -f install出现了：
(E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied)
E: Unable to lock the administration directory (/var/lib/dpkg/), are you root?)
我接下来该怎么做？我无法更新我的电脑。我还想同时安装 Windows XP。