Registry is a database which stores the s/w and hardware information of a computer.This resides(contains) in the file user.dat and system.dat from windows 95 version onwards ; before that there was no concept of registry apart from this all informations are stored in the following files Config.sys,autoexec.bat,system.ini,control.ini,win.ini. For editing the registry files windows supplies 'Regedit' named tool .Registry details can be exported and imported .Exported registry files with be .reg extension ;its a text based file.
REGEDIT4
[HKEY_LOCAL_MACHINE\SYSTEM\Setup]
"setup type"=dword.00000000
"cmdline"=setup_new setup
"System Perfix"=hex:c5,0b,00,00,40,36,02
In registry the hyphone symbol '-' is used for commenting.
Based upon the information registry is divided into 6 sections.
HKEY_CLASSES_ROOT
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This section contains the information of different type of file extensions,OLE related details,Drag & drop features ,Windows shortcut ,User interface etc.
HKEY_CURRENT_USER
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Contains the information of login user detials and their desktop and start menu settings.
HKEY_LOCAL_MACHINE
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This stores information about hardware and s/w details .There are many subkeys in this section
Config :
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Contains information about assemblence of different hardwares .
Enum :
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It contains all details about device drivers in the PC.
Hardware :
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It contains information about Serial Port ,Processors,Floating Point Processers etc
Network :
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Network related details .
Software :
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Information about What all Softwares installed in the PC.
System :
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It deals with information about the device drivers which is uesd in the Pcand its assembly details.
HKEY_USERS
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Contains the information of all user detials and their desktop and start menu settings.
HKEY_CURRENT_CONFIG
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Details about Hardware Configuration.
HKEY_DYN_DATA
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In registry there are 5 different datatypes
1) REG_BINARY : This datatypes are used for mainly storing hardware related informations .Its value is shhown in hexadecimal format.
2) REG_DWORD : This is 4 byte in length ,consist of boolean data 0 and 1 .Its value can be seen in hexadecimal or in decimal format .
3) REG_SZ : String datatype.
4) REG_EXPAND_SZ :
5) REG_MULTI_SZ :