When we look at the usage data of how people are using the Start menu to search in Windows 7, it’s clear that searching to launch programs is the most frequent and important activity users engage in with Start search.
Our telemetry data shows that 67% of all searches in Windows 7 are used to find and launch programs. Searching for files accounts for 22% of all Windows 7 Start menu searches, and searching for Control Panel items about 9%. Searching for email messages via Start Menu is very rare (less than 0.05%). The remaining 2% are searches executing the “Run” functionality.
To give you an example, if you typed "power" into the search box, most of the time you would be looking for PowerShell, not Power Options.
In Windows 8, we expect people will be acquiring and installing more apps than ever before. Had we continued using the Windows 7 Start menu search interface to search for a Control Panel item, you would always see app or program results before Control Panel results, displacing many Control Panel items from being the first match. This and other constraints on the existing design required us to develop a new approach—this is especially true as we consider the increasing use of larger monitors or higher DPI screens where longer menus become even more difficult to use and navigate. In Windows 7, the total number of results that could be shown in the Start menu was limited. Depending on the number of groups with matching results, an average of 3-4 results were shown per group. Very rarely did all results for a group show up, and the organization of the results was pretty unpredictable.