With the Search charm (

+F), you can search for anything. You can search just the app you're in (like finding a specific message in Mail), search another app (like looking up something on the Internet), or search your entire PC (for an app, setting, or file).
Search your PC. When you’re on the Start screen or desktop, you can search your whole PC. Open the charms, tap or click Search, enter a term, and you’ll see the results. You can filter the search results to show apps, settings, or files, depending on what you're looking for. Tip: To search from the Start screen, you don’t even need to open the charms. Just start typing!
Search your apps. If you’re using an app, you can search just that app. For example, you can find specific email messages in the Mail app or look up meetings in the Calendar app. From within the app, open the charms, tap or click Search, and then enter what you're looking for.
Search the Internet. You can also search the web from anywhere on your PC. Open the charms, tap or click Search, enter your search term, and then tap or click Bing. You'll see Bing results for whatever you’re searching for.