How may I change the default double-click image viewer to Picasa? Thank you for your assistance . . . .
IMatch uses the same
associated application as Windows.
Select a file in File Window and press <Alt>+<Enter> to open the Windows Explorer context menu.
Choose the
Open with... > Choose another app command. Select the app you want to associate with the file format and enable the "Always" option. See the Windows help for details.