More advanced option: Uses registry changes to add item to Context menu of image file.
One better way to associate the viewer is to add an item to the Right Click Context menu of files like jpegs. In the menu it can say something like Open with Windows Picture and Fax Viewer. My walk through will do this for jpeg files without changing their existing associations.
Step 1: Open RegEdit and go to HKEY_CLASSES_ROOT | jpegfile
Step 2: Under jpegfile go to shell. Right click on shell and New | Key, name it something like Open.Viewer
Step 3: In Open.Viewer double click on (Default) in the right pane and type in what you want the Context Menu item to say. aka
Open In Windows Fax and Picture Viewer
Step 4: Right click on Open.Viewer and New | Key, name it command
It must be named command all lowercase
Step 4: In command double click on (Default) in the right pane and type in the path to shimgvwdll
rundll32.exe c:\windows\system32\shimgvw.dll,ImageView_Fullscre en %1
The %1 at the end is critical
Step 5: Right click on a jpeg/jpg file and in the menu should be the Open in Windows... item. Should open the file. You can also add in printing capabilities as well. The article I reference on all this is at...
Microsoft MSDN Article
Hope it helps / works for you