Data Types in the Registry

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Data types define what kind of data a registry entry can store. The Windows Server 2003 registry uses the following data types:

REG_SZ

A fixed-length text string. Boolean ("True" or "False") values and other short text values usually have this data type. For an example, see the Pattern Entry entry.

REG_EXPAND_SZ

A variable-length text string. REG_EXPAND_SZ data can include variables that are resolved when an application or service uses the data. For example, the value of the File entry includes the variable %systemroot%. When the Event Log service references this entry, the variable is replaced by the name of the directory containing the Windows Server 2003 system files.

REG_MULTI_SZ

Multiple text strings formatted as an array of null-terminated strings, and terminated by two null characters. Entries that contain lists or multiple data in a readable form are usually this data type. The values in a REG_MULTI_SZ entry can be separated by spaces, commas, or other marks. For an example, see the value of the Machine entry, which is a list of paths accessible by all remote users.

REG_BINARY

Raw binary data. Most hardware component information is stored as binary data. It can be displayed in an easy-to-read format by using Windows Server 2003 Diagnostics. For an example, see theCustomColors entry.

REG_DWORD

A 32-bit (4-byte) number. Boolean ("True" or "False") values and many entries for device drivers and services use this data type. REG_DWORD data can be displayed and entered in hexadecimal or decimal format in the registry editor Regedit.exe. For an example, see the ActivityLogFlag entry.

REG_DWORD_BIG_ENDIAN

Same as REG_DWORD. A 32-bit number in which the most significant byte is displayed as the leftmost (or high-order) byte. This is the most common format for storing numbers in computers that are running Windows Server 2003.

REG_DWORD_LITTLE_ENDIAN

A 32-bit number in which the most significant byte is displayed as the rightmost (or low-order) byte. This is opposite of the order in which bytes are stored in the REG_DWORD and REG_DWORD_BIG_ENDIAN data types.

Indicates a symbolic link between system or application data and a registry value. You can use Unicode characters in a REG_LINK entry.

REG_FULL_RESOURCE_DESCRIPTOR

A series of nested arrays designed to store a resource list for a hardware component or driver.