Here is a simple way to add MDViewer to the Explorer context menu for an easy way to open files.
To do this you will need to update the following registry info and save it to a .reg file. Make sure to update the path to the path to where you have MDViewer.exe
Snippit (change the path in bold to your location)
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT*\shell\Open with MDViewer]
[HKEY_CLASSES_ROOT*\shell\Open with MDViewer\command]
@=”C:\Program Files\MDViewer_1.1.0\MDViewer.exe %1″
Now you just save to a .reg file and run it and poof you can now open files with MDViewer from explorer.