From the MSIExplorer window:

• Select the Search context(s) you want to delete (multiple selection allowed)
• Right-click to display context menu and choose Delete…

From the MSIExplorer window,

• Select the User context(s) you want to delete (multiple selection allowed)
• Right-click to display context menu and choose Delete…

If the context to delete was a parent content (i.e. this context has child context(s)), these child contexts will them become root contexts.

• Known Bug : when deleting a context, a save is automatically done on the MS Identification database
• If a user context is a child, a message box will be displayed and context will not be deleted