i bought this sw on the understanding that all these nas s/w operating systems is that you can add addons like SABnzbd ( pythin script) i cant however see where to install any such things?
can i install it ?
On who's understanding? If you had read the manual or posted questions here first you would have been told that the definitive answer is no! My guess is that you just assumed and acted without asking first. At least it wasn't a software package that ran several hundred Dollars.
NASLite is not about reading news or running python scripts, it is about NAS and NAS only. You don't have access to a command line. You don't have the ability to set user access controls and levels. It does one thing, server files via a number of protocols. It is light weight, fast, easy to configure, supports a large array of hardware, and is very reliable. Allot of these attributes would not be so if the developers were to allow you to reconfigure the software. Anything you wanted to run in addition to the basic NASLite OS/appliance would very likely bring with it a sacrifice in reliability, stability, and speed. In addition, the NASLite software does not include most of the things taken for granted in normal distros like Xwindows and drivers for fancy 3D video cards, office apps, games, etc. These serve no purpose and take up space and/or resources that are better used for NAS. The kernel has only that which is necessary and so it is very likely that you would not even be able to get the software running on it without allot of patching and additional packages.
Hope this clears up your obvious confusion. On the plus side you may find that set it and forget it NASLite is quite a thing to marvel at. When you start to forget about an appliance, then it is truly a great thing.