Inside Windows 8: PC Settings – Search
In Windows 8, you can configure search a lot more than on previous Windows Operating Systems.
You can get to this from the Charms > Settings > More PC Settings > Search
You can delete all search history from your computer.
You can also let Windows save your searches so it can suggest them to you in the future.
You can organize the apps that you search by most frequently searched apps.
Finally, you can select which apps are allowed to be searched and which apps are off-limits.