Get the appropriate installer here
For Maya 2012 64 bit get the pywin32-217.win-amd64-py2.6.exe
For Maya 2012 32 bit get the pywin32-217.win32-py2.6.exe
Run the downloaded executable, it should install to your C:\Python26\Lib\site-packages.
Copy the contents of that folder to your C:\Program Files\Autodesk\Maya2012\Python\lib\site-packages.
That should do it!
Of course be aware of what other packages you had installed previously in both site package folders, if you're concerned about overwriting something.