During the installation process, you are given the opportunity to select additional software to install. Rather than picking individual software packages from the &num-of-distrib-pkgs; available packages, this stage of the installation process focuses on selecting and installing predefined collections of software to quickly set up your computer to perform various tasks. So, you have the ability to choose tasks first, and then add on more individual packages later. These tasks loosely represent a number of different jobs or things you want to do with your computer, such as Desktop environment, Web server, or Print server You should know that to present this list, the installer is merely invoking the tasksel program. It can be run at any time after installation to install more packages (or remove them), or you can use a more fine-grained tool such as aptitude. If you are looking for a specific single package, after installation is complete, simply run aptitude install package, where package is the name of the package you are looking for. . lists the space requirements for the available tasks. Some tasks may be pre-selected based on the characteristics of the computer you are installing. If you disagree with these selections you can un-select the tasks. You can even opt to install no tasks at all at this point. The Desktop environment task will install the GNOME desktop environment. The options offered by the installer currently do not allow to select a different desktop environment such as for example KDE. It is possible to get the installer to install KDE by using preseeding (see ) or by adding tasks="standard, kde-desktop" at the boot prompt when starting the installer A more lightweight Xfce desktop environment can be selected by using xfce-desktop instead of kde-desktop. If you are installing on a laptop, you could also add laptop to the tasks to be installed. . However, this will only work if the packages needed for KDE are actually available. If you are installing using a full CD image, they will need to be downloaded from a mirror as KDE packages are not included on the first full CD; installing KDE this way should work fine if you are using a DVD image or any other installation method. The various server tasks will install software roughly as follows. DNS server: bind9; File server: samba, nfs; Mail server: exim4, spamassassin, uw-imap; Print server: cups; SQL database: postgresql; Web server: apache. Once you've selected your tasks, select &BTN-CONT;. At this point, aptitude will install the packages that are part of the tasks you've selected. In the standard user interface of the installer, you can use the space bar to toggle selection of a task. You should be aware that especially the Desktop task is very large. Especially when installing from a normal CD-ROM in combination with a mirror for packages not on the CD-ROM, the installer may want to retrieve a lot of packages over the network. If you have a relatively slow Internet connection, this can take a long time. There is no option to cancel the installation of packages once it has started. Even when packages are included on the CD-ROM, the installer may still retrieve them from the mirror if the version available on the mirror is more recent than the one included on the CD-ROM. If you are installing the stable distribution, this can happen after a point release (an update of the original stable release); if you are installing the testing distribution this will happen if you are using an older image. Each package you selected with tasksel is downloaded, unpacked and then installed in turn by the apt-get and dpkg programs. If a particular program needs more information from the user, it will prompt you during this process.