To edit session settings
1.Pick Session > Session Settings 
.
2.Modify the desired settings on each tab.
3.The dropdown list at the bottom of the dialog controls the scope of your changes. Pick Use for this view only to affect the current session, or Update session defaults to apply your changes to all new sessions of this type.
Additional choices are shown for child sessions, comparisons spawned from a folder session. Use for these files within parent session causes the current folder session to remember these settings and use them whenever this particular pair of files is compared. Use for all files within parent session causes these settings to be used for any new sessions of this type spawned from the current folder session.
4.Click OK.
Specific settings for session types
