A. Similar to file shortcuts that point to an actual file, registry links create a symbolic link from a virtual path to an actual path. You might have seen these links in the HKEY_LOCAL_MACHINE\CurrentControlSet registry subkey, which is a link to one of the ControlSets under the same parent location, and the HKEY_CURRENT_USER registry key, which points to a path under HKEY_USERS\<SID of current user>.
Both of these registry links are of type REG_LINK, but you can't use standard registry tools to create this internal type. However, a freeware utility available from the NTinternals Team at http://www.ntinternals.net/regln lets you create registry links. Be sure to read the instructions before you dive in, and treat this utility with care; otherwise, you might cause serious damage to your machine.