What program opens MDI files?
The program that opens .mdi files can be run by selecting the start menu button, select Microsoft Office -> Microsoft Office Tools -> Microsoft Office Document Imaging. To link .mdi files to the correct program, right-click the .mdi file and select Open With -> Choose Program… In the Windows dialog that opens, click on the “Select the program from a list” radio button. In the Open With dialog that follows, click the checkbox for “Always use the selected program to open this kind of file”, then select the Browse… button. Browse to “C:\Program Files\Common Files\Microsoft Shared\MODI\11.0\”, select MSPVIEW.EXE, then click the Open button. You’re done!