Installing VirtualBox From Precompiled Binaries

First, we install the packages gdeb, gedbi, and gdebi-core. Open the Synaptic Package Manager (System > Administration > Synaptic Package Manager):

You can use the search function to find the three packages. Select them for installation and click on Apply. Close Synaptic after the packages have been installed:

Open Firefox and go to http://www.virtualbox.org/wiki/Linux_Downloads. For Debian Lenny, click on the i386 or AMD64 link (depending on if you have a 32 or 64 bit host operating system) right of Debian 5.0 ("Lenny"):

In the Firefox download dialogue, select Save File…

… and download the package, e.g. to your desktop (/home/falko/Desktop in this example):

After the download has finished, open a terminal (Applications > Accessories > Terminal)…

… and type

su

to become root.

Then run

gdebi /home/falko/Desktop/virtualbox-2.1_2.1.4-42893_Debian_lenny_i386.deb

to install VirtualBox (make sure you use the correct path; also the package name can differ, for example if you have downloaded the amd64 version or if there is a newer version – use the TAB key to use autocompletion in the terminal).

During the installation you will see the following message. It says that the user that runs VirtualBox – that's the user you're logged in as on your desktop – must be a member of the vboxusers group:

To add the user falko to the vboxusers group, we run

usermod -G vboxusers -a falko

in the terminal, delete the VirtualBox package…

rm -f /home/falko/Desktop/virtualbox-2.1_2.1.4-42893_Debian_lenny_i386.deb

… and close the terminal afterwards.

To start VirtualBox, go to Applications > System Tools > Sun xVM VirtualBox (if you don't see the VirtualBox launcher, log out of the desktop and back in again):

When you start VirtualBox for the first time, you are prompted to accept its license:

Afterwards, type in your name and email address to register your VirtualBox installation:

Click on OK in the registration confirmation window:

That's it! You can now use VirtualBox to create virtual machines:

 

Src: http://www.miniwiki.org/wiki/index.php?wiki=_content.www.howtoforge.com%2Finstalling-virtualbox-2-on-a-debian-lenny-desktop