There is a builted-in PDF reading app in Windows 8 Pro and is the default PDF reader. Now Adobe Corporation has released their Adobe Reader app with touch interface and many useful features from the Windows Store. If you have installed the the free Adobe Reader app and want to set it up as the default PDF reading app in Windows 8 Pro or Surface Rt tablet, here is the steps about how to do that.
* Go to any PDF file and right-click on it. Click/tap “Open with” and select Choose default program.
* You will see lots of apps are listing there. Choose Adobe Reader and check “Use this app for all .pdf files”.
* You can also try another method. Open charms bar from Start screen, type Default Programs from search and press Enter. Click Set your default programs > Adobe Reader on the left pane > Set this program as default on the right.