I am a php developer. For easy installation of php+apache+mysql there is WAMP, xampp, etc.
my internet connection is bad quality. and unable to use npm install. i want download a single setup file that installs node.js, socket.io, expressjs and etc
I am not aware of any package similar to WAMP for Node.js. Nonetheless, you can grab Node.js Windows installer from here: http://nodejs.org/#download. Please note that the only embedded tool is npm.
If you can not use npm directly, getting all the dependencies will be a real mess. Most of the packages you will need (socket.io and express for example) in turn have multiple dependencies.
Anyway, it is still possible to use npm from manually downloaded files. Look at http://npmjs.org/doc/install.html for more informations.
You can download packages manually at http://search.npmjs.org. There is no single setup that downloads any possible configuration of npm packages, you would have to download them one at a time but that should be able to grab them even on a very slow connection.
The other option would be to grab them directly from their GitHub location since that's where most of them are hosted. You could sync the source using git and then install them. That should also work on a slow connection.