See this step by step guide for installing Mandriva 2009 with LXDE.
http://lordikc.free.fr/wordpress/?page_id=334
Lots of pictures so it is accessible to everybody.
LXDE with Mandriva 2009
Re: LXDE with Mandriva 2009
It is also as simple as installing the task-lxde package. This will auto-select and install all of the packages to install LXDE under Mandriva.
As root, at a command prompt: urpmi task-lxde
As root, at a command prompt: urpmi task-lxde
Debian Sid - LXDE