The availability and quality of Open-Source GI-S Software is rapidly increasing.
Basically the installation of free/open source GIS software is very straightforward on your own computer.Osgeo4w has an almost complete support of the Open Source geo-software for the Windows OS. Linux systems are also excellent supported ( UbuntuGIS, OpenSuse GEO Repo). However you have to do some manual work to install it properly.
Nevertheless the experience has shown that in the context of centrally managed PC-Labs and the high diversity of operating systems and individual computer configurations you won't find hardly comparable working conditions. Both technically slowed down and confronted with numerous “incompatibilities” it is seems to be challenging to have a positive start in the world of spatial data. Because of this just a few beginners overcome the barriers and start over in the fascinating world of GI.
To facilitate the usability of GIS in a heterogeneous technical environment and to help beginners and those who want to switch from commercial software various open source GIS packages are bundled.
The two choices are periodically brought to a current and stable state. For details have a look on each of the linked pages.