Maximizer defaults to using Microsoft Office Document Imaging to open .tif files. Is there a way to have it open them with another application, specifically Windows Picture and Fax Viewer

I wonder if Maximizer is deciding or if it is using your Windows file extension association? If you click on a .tif file in Windows explorer what program is used to view the .tif file?

By default Maximizer will open the file using whatever program windows associates with it. You can change file associations by clicking Tools>>Folder Options in Windows Explorer and go to the File Types tab.