Windows 8 In Depth

Registry Virtualization

In the days before Windows security became a serious concern, many applications stored information in keys under HKLM, typically in a key named along the lines of HKLM\Software\ManufacturerName\ApplicationName, so that the information could be made available to all users on the computer. Imagine a game that keeps track of the highest score achieved by any user. It has to store that high score somewhere accessible to all users, and HKLM is exactly such a place. So, versions of Windows up to XP let any application write to this key or its subkeys. This became an enormous security problem, because this also made it very easy for malware to make changes to global Windows settings affecting all users.

User Account Control, ...