This is one of the most annoying issues with Adobe, where you do not know have any idea on what is going in since the issue doesn’t produces any error, it simply closes itself when you try to open Adobe Reader directly or any of the pdf files that are supposed to open using the Adobe Reader.
The reason why it occurs is when the Adobe thinks that you have not accepted their terms of using Adobe. To fix the issue, you will need to run the Eula.exe app from the Adobe’s folder and accept the licensing terms. On Windows 7 computers, the folder you need to look into is
Once you are in the Adobe folder, click Reader (your version) and open the Reader folder locate the file Eula.exe. Double Click the Eula.exe file and Click Accept to accept the licensing terms. Your Adobe Reader should now open fine.