Users can create multiple different desktops for themselves and easily switch between these desktops. These multiple desktops are "walled off" from one another, limiting the ability of processes and other subjects in one desktop from accessing objects, such as data files or other processes, in another desktop. According to one aspect, each time a process is launched it is associated with the desktop that it is launched in. Similarly, objects, such as data files or resources, are associated with the same desktop as the process that created them. The operating system allows a process to access only those objects that are either associated with the same desktop as the process or associated with no desktop.