The current windows installer from nodejs.org as of v0.6.11 (2012-02-20) will install NPM along with NodeJS.
NOTES:
At this point, the 64-bit version is your best bet
The install path for 32-bit node is "Program Files (x86)" in 64-bit windows.
You may also need to add quotes to the path statement in environment variables, this only seems to be in some cases that I've seen.
In Windows, the global install path is actually in your user's profile directory
%USERPROFILE%\AppData\Roaming\npm
%USERPROFILE%\AppData\Roaming\npm-cache
WARNING: If you're doing timed events or other automation as a different user, make sure you run npm install as that user. Some modules/utilities should be installed globally.
INSTALLER BUGS: You may have to create these directories or add the ...\npm directory to your users path yourself.
To change the "global" location for all users to a more appropriate shared global location %ALLUSERSPROFILE%\(npm|npm-cache) (do this as an administrator):
create an [NODE_INSTALL_PATH]\etc\ directory
this is needed before you try npm config --global ... actions
create the global (admin) location(s) for npm modules
C:\ProgramData\npm-cache - npm modules will go here
C:\ProgramData\npm - binary scripts for globally installed modules will go here
C:\ProgramData\npm\node_modules - globally installed modules will go here
set the permissions appropriately
administrators: modify
authenticated users: read/execute
Set global configuration settings (Administrator Command Prompt)
npm config --global set prefix "C:\ProgramData\npm"
npm config --global set cache "C:\ProgramData\npm-cache"
Add C:\ProgramData\npm to your System's Path environment variable
If you want to change your user's "global" location to %LOCALAPPDATA%\(npm|npm-cache) path instead:
Create the necessary directories
C:\Users\YOURNAME\AppData\Local\npm-cache - npm modules will go here
C:\Users\YOURNAME\AppData\Local\npm - binary scripts for installed modules will go here
C:\Users\YOURNAME\AppData\Local\npm\node_modules - globally installed modules will go here
Configure npm
npm config set prefix "C:\Users\YOURNAME\AppData\Local\npm"
npm config set cache "C:\Users\YOURNAME\AppData\Local\npm-cache"
webpack - module bundler, package node-style modules for browser usage
babel - convert modern JS (ES2015+) syntax for your deployment environment.
If you build it...
shelljs - shell utilities for node scripts,. I used to use gulp/grunt, but these days will have a scripts directory that's referenced in package.jsonscripts via npm. You can use gulp tools inside plain scripts.
I've just installed 64 bit Node.js v0.12.0 for Windows 8.1 from here.
It's about 8MB and since it's an MSI you just double click to launch. It will automatically set up your environment paths etc.
Then to get the command line it's just [Win-Key]+[S] for search and then enter "node.js" as your search phrase.
Choose the Node.js Command Prompt entry NOT the Node.js entry.
Both will given you a command prompt but only the former will actually work. npm is built into that download so then just npm -whatever at prompt.
Create folders c:\nodejs\node_modules and c:\nodejs\node_modules\npm
Unzip the downloaded zip file in c:\nodejs\node_modules\npm folder
Copy npm and npm.cmd files from c:\nodejs\node_modules\npm\bin to c:\nodejs folder
In order to test npm, open cmd.exe change working directory to c:\nodejs and type npm --version. You will see the version of npm if it is setup correctly.
Once setup is done, it can be used to install/uninstall packages locally or globally. For more information on using npm visit https://docs.npmjs.com/.
As the final step you can add node's folder path c:\nodejs to the path environment variable so that you don't have to specify full path when running node.exe and npm at command prompt.
I just installed Node.js for the first time and it includes NPM, which can be ran from the Windows cmd. However, make sure that you run it as an administrator. Right click on cmd and choose "run as administrator". This allowed me to call npm commands.