Windows Registry primarily stored configuration information for COM based components. Windows 9. 5 and Windows NT extended its use to rationalise and centralise the information in the profusion of INI files, which held the configurations for individual programs, and were stored at various locations. It is not a requirement for Windows applications to use the Windows Registry. For example,. NET Framework applications use XML files for configuration, while portable applications usually keep their configuration files with their executables. RationaleeditPrior to the Windows Registry,. INI files stored each programs settings as a text file, often located in a shared location that did not provide user specific settings in a multi user scenario. By contrast, the Windows Registry stores all application settings in one logical repository but a number of discrete files and in a standardized form. According to Microsoft, this offers several advantages over. INI files. 23 Since file parsing is done much more efficiently with a binary format, it may be read from or written to more quickly than an INI file. As well, strongly typed data can be stored in the registry, as opposed to the text information stored in. INI files. This is a benefit when editing keys manually using regedit. Windows Registry Editor. Because user based registry settings are loaded from a user specific path rather than from a read only system location, the registry allows multiple users to share the same machine, and also allows programs to work for less privileged users. Backup and restoration is also simplified as the registry can be accessed over a network connection for remote managementsupport, including from scripts, using the standard set of APIs, as long as the Remote Registry service is running and firewall rules permit this. Because the registry is a database, it offers improved system integrity with features such as atomic updates. If two processes attempt to update the same registry value at the same time, one processs change will precede the others and the overall consistency of the data will be maintained. Where changes are made to. INI files, such race conditions can result in inconsistent data that does not match either attempted update. Windows Vista and later operating systems provide transactional updates to the registry by means of the Kernel Transaction Manager, extending the atomicity guarantees across multiple key andor value changes, with traditional commitabort semantics. Note however that NTFS provides such support for the file system as well, so the same guarantees could, in theory, be obtained with traditional configuration files. StructureeditKeys and valueseditThe registry contains two basic elements keys and values. Registry keys are container objects similar to folders. Registry values are non container objects similar to files. Keys may contain values and subkeys. Keys are referenced with a syntax similar to Windows path names, using backslashes to indicate levels of hierarchy. Keys must have a case insensitive name without backslashes. The hierarchy of registry keys can only be accessed from a known root key handle which is anonymous but whose effective value is a constant numeric handle that is mapped to the content of a registry key preloaded by the kernel from a stored hive, or to the content of a subkey within another root key, or mapped to a registered service or DLL that provides access to its contained subkeys and values. E. g. HKEYLOCALMACHINESoftwareMicrosoftWindows refers to the subkey Windows of the subkey Microsoft of the subkey Software of the HKEYLOCALMACHINE root key. There are seven predefined root keys, traditionally named according to their constant handles defined in the Win. API, or by synonymous abbreviations depending on applications HKEYLOCALMACHINE or HKLMHKEYCURRENTCONFIG or HKCCHKEYCLASSESROOT or HKCRHKEYCURRENTUSER or HKCUHKEYUSERS or HKUHKEYPERFORMANCEDATA only in Windows NT, but invisible in the Windows Registry EditorHKEYDYNDATA only in Windows 9x, and visible in the Windows Registry EditorLike other files and services in Windows, all registry keys may be restricted by access control lists ACLs, depending on user privileges, or on security tokens acquired by applications, or on system security policies enforced by the system these restrictions may be predefined by the system itself, and configured by local system administrators or by domain administrators. Different users, programs, services or remote systems may only see some parts of the hierarchy or distinct hierarchies from the same root keys. Registry values are namedata pairs stored within keys. Registry values are referenced separately from registry keys. Each registry value stored in a registry key has a unique name whose letter case is not significant. The Windows API functions that query and manipulate registry values take value names separately from the key path andor handle that identifies the parent key. Registry values may contain backslashes in their names, but doing so makes them difficult to distinguish from their key paths when using some legacy Windows Registry API functions whose usage is deprecated in Win. The terminology is somewhat misleading, as each registry key is similar to an associative array, where standard terminology would refer to the name part of each registry value as a key. The terms are a holdout from the 1. Adobe Acrobat Does Not Find Scanner On Computer there. Windows 3, in which registry keys could not contain arbitrary namedata pairs, but rather contained only one unnamed value which had to be a string. In this sense, the entire registry was like a single associative array where the registry keys in both the registry sense and dictionary sense formed a hierarchy, and the registry values were all strings. When the 3. 2 bit registry was created, so was the additional capability of creating multiple named values per key, and the meanings of the names were somewhat distorted. For compatibility with the previous behavior, each registry key may have a default value, whose name is the empty string. Each value can store arbitrary data with variable length and encoding, but which is associated with a symbolic type defined as a numeric constant defining how to parse this data. The standard types are List of standard registry value types. Type IDSymbolic type name. Meaning and encoding of the data stored in the registry value. REGNONENo type the stored value, if any1. REGSZA string value, normally stored and exposed in UTF 1. LE when using the Unicode version of Win. API functions, usually terminated by a NUL character. Download Microsoft Diagnostics And Recovery Toolkit V5© 2017