NGELlinux desktop is similar to windows in work and feel.
You can either replace it with windows or can install alongwith windows OS.
First Install Windows and thereafter install NGELinux from its DVD.
Just follow the installation steps after booting from CD and it will be installed.
However most of the requried packages/softwares are already available on NGELinux, or otherwise can be installed from Centos repositories configured on the system.