Whenever you open up programs that are frequently used, these are saved in system’s cache to load them up easily when you want to open them up again. This feature is only for Windows Store. If you want to enable or disable to store recently opened programs in Windows 8, here is how you can do it:
1. Right click anywhere on the empty taskbar and click Properties
2. Now go to Jump Lists and check or uncheck Store recently opened programs to enable or disable this feature.