Some useful links:
[Download Windows Essentials 2012][1]Download Windows Essentials 2012
[Windows Essentials 2012 Release Notes][2]Windows Essentials 2012 Release Notes
[Install Windows Essentials Offline][3]Install Windows Essentials Offline
I am very glad to inform that Windows Photo Gallery is a nice piece of software for photo management. The feature of it which I like most is the picture editing tools, it allows you to change each parametre as you like, rather than one-click way in Picasa.
To answer my own question, you cannot install Photo Gallery alone(AFAIK), but along with movie maker. You may exclude the other utilities(OneDrive, Family Safety, Mail, Writer).
[1]: http://windows.microsoft.com/en-in/windows-live/photo-gallery
[2]: http://windows.microsoft.com/en-in/windows/essentials-2012-release-notes
[3]: http://windows.microsoft.com/en-IN/windows-live/essentials-install-offline-faq