[colore]

hello

I want to write my own window manager / shell for windows xp

where do I start?

thanks

[Yzöwl]

Do you know any programming? if so what language(s) and what level of knowledge do you have?.

I would also suggest you'd need a thorough knowledge of the internal workings of the Windows OS you are intending to build this for too!

[Nuno Brito]

You can start from scratch or pick a project already in development and join the team effort.

BBlean is a good option, open source and very efficient: http://www.bb4win.org/news.php
ReactOS comes with an open source shell that you can also use: http://www.sky.franken.de/explorer/

Personally, I recommend getting in contact with an already estabilished project as they can guide you and maybe this way save a lot of time rather than learning everything from scratch.