I'm trying to install the Guest Additions in VirtualBox 4.04. Host OS is Ubuntu desktop 11.04 64bit, guest OS is Ubuntu server 11.10 64bit. $ sudo ./VBoxLinuxAdditions.run After some output this line is printed: The headers for the current running kernel were not found. But the headers are installed, at least accordingly to dpkg: $ dpkg --get-selections | grep linux-headers linux-headers-3.0.0-12