When you search for apps in Windows, it creates a history of them and shows the most searched ones on the top when you search for them. Here is how you can change these settings in Windows 8:
1. Open up PC Settings by moving your mouse over to the top right corner of the screen to activate the Charms Bar. Now click on PC Settings.
2. On the left side, click Search and on the right side, move the slider to on or off to enable or disable Show the apps I search most often at the top