This is a strange issue.! Could you please help me here with a few details:
1. Could you post a screenshot of the blank window that you are getting?
2. Also, when you say that you are able to view PDFs in the browser, can you please let me know which browser are you using?
3. Do you still have Adobe Acrobat Pro X installed on the system? You can check the same by checking for its presence in the Programs and Features dialog from within the Control Panel.
4. Try and launch Adobe Reader and chose Edit > preferences > General. Click on the "Select Default PDF Handler" button. In the window that appears, what is the dropdown value selected? Try changing it to Adobe Reader X (10.1.3) if its set to some other value.