configuring centralised update

How do I configure a centralised update in a microsoft network. I dont want all clients connecting to the microsoft update server- bandwidth you know

You could look into setting up a Windows Software Update Server (WSUS). This downloads the updates from Microsoft and you then deploy them locally. I believe WSUS is being/has been superceded by an other more up-to-date arrangement recently but I'm not sure so you might want to check

I used WSUS with great success. I believe it had a web interface as well. You could create groups and allow/deny specific updates. Worked pretty well.

how about in linux

You want to do the same thing for all Linux machines? No idea on that one. Sorry.

on linux there is a central update repository which does central update. its called apt-cacher and you can use it to cache any software installed via apt-get (a package management tool used in debian linux) and stores it locally in the apt-caher should anysystem on the network need same package. it would be downloaded from the apt-cacher instead. the process works smoothly and saves a lots of bandwidth.