Vista introduced search from the Start menu as well as inside Explorer, for programs as well as documents, but it was often slow; the Windows Desktop 4 update in SP2 did improve this slightly.
Windows 7 makes search significantly faster and as well as installed applications it now searches all the control panel settings, using synonyms to make it easier to find what you want.
SEARCH: Within five seconds of adding this folder to the library we got search results in the Start menu from it
It also incorporates the OpenSearch protocol; Microsoft talks about this as a way of finding business documents on SharePoint sites, but with the right XML file to set it up you can search web services like Flickr from Explorer.
Search is what drives the new Libraries as well; they're a saved search across as many folders as you want.
Libraries sort your media and files so that you can view them all in one place, even if they're scattered across multiple folders on multiple storage devices.
LIBRARY: Link all the places you store pictures, video and music
What you get is a combined view of multiple folders at once, so if you have photos on your PC, on an external hard drive and on a NAS box you can see them all together. This is the way media libraries in Windows Media Player have worked for a long time, but you can use libraries in any application.
They get their own ways of organising content, so the video library can sort files into full length and short clips while the document library has options like Author and Tag.
There's also a new Content view in Explorer that gives you mini-thumbnails and document metadata at the same time.
PARENTAL CONTROL: You have the option to plug in third-party security software
Other tweaks in Explorer fit more thumbnails into less space and put a New Folder and Preview Pane button on the toolbar all the time for convenience.
One popular Vista feature is still in Windows 7 but oddly it's turned off by default; check boxes to make it easier to select multiple files without accidentally losing everything you've already picked.