As long as you hold at least one instance on a MemoryFile or a MemoryFolder located in a specific root name, all files and folders in that same virtual ram drive stay alive. When a root name is no longer referenced, all its content will get garbage collected later.
To make sure the memory allocated for a MemoryFile's data is released, as soon as you don't need the file anymore, call FileSystemItem.Delete on that MemoryFile.
Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2