The Update All context menu item is missing when you right-click the My Briefcase folder.
If the Update All context menu is missing, open My Briefcase folder and use the Briefcase menu, or the Common Tasks pane to update all items.
The Update All context menu entry can be restored using these steps:
HKEY_CLASSES_ROOT\Folder\shellex\ContextMenuHandlers
{85BBD920-42A0-1069-A2E4-08002B30309D}