1. Windows Registry Application Developer Issues SIG North Texas PC Users Group January 11, 2003 Daniel Ogden SIG Co-Leader http://appdevissues.tripod.com http://appdevissues.tripod.com/downloads.htm

2. Windows Registry  Windows Registry Settings (From Windows Customization presentation of 12-14-2002)  Not for the faint of heart  Contrary to Microsoft and other’s recommendations, use “regedit.exe” rather than “regedt32.exe” for most registry operations  Permissions  Saving of keys as “Favorites”  Local run/Current User run  Default separate vdm  Current Control Set

3. Windows Registry  Scope of Presentation  Windows NT 4.0/2000/XP only  Registry Structure  Registry Elements  Registry in Windows Boot Process  Registry Security  Registry Customization

4. Windows Registry  Registry Structure  Subtree-Root Level of the Registry  Five Subtrees-  HKEY_LOCAL MACHINE Local system hardware, device drivers, services, and machine- specific application data information.Local system hardware, device drivers, services, and machine- specific application data information.  HKEY_USERS Pre-logon default user profile information and HKEY_CURRENT_USER keyPre-logon default user profile information and HKEY_CURRENT_USER key  HKEY_CURRENT_USER Currently logged on user profile informationCurrently logged on user profile information  HKEY_CLASS_ROOT Software configuration information from the HKEY_LOCAL MACHINE\SOFTWARE\Classes keySoftware configuration information from the HKEY_LOCAL MACHINE\SOFTWARE\Classes key  HKEY_CURRENT _CONFIG Hardware information from the HKEY_LOCAL MACHINE\SOFTWARE and HKEY_LOCAL MACHINE\ SYSTEM keysHardware information from the HKEY_LOCAL MACHINE\SOFTWARE and HKEY_LOCAL MACHINE\ SYSTEM keys

5. Windows Registry  Registry Elements  Keys/Subkeys  Defines the structure of the registry  Similar to folders in a file system  Values  Contains Registry data in specific subkeys  Five types of values String value (REG_SZ)-Single line string valueString value (REG_SZ)-Single line string value Binary value (REG_BINARY)-Binary valueBinary value (REG_BINARY)-Binary value DWORD value (REG_DWORD)-Doubleword value up to four bytes longDWORD value (REG_DWORD)-Doubleword value up to four bytes long Multi-string value (REG_MULTI_SZ)-Multiple line string valueMulti-string value (REG_MULTI_SZ)-Multiple line string value Expandable string value (REG_EXPAND_SZ)-Expandable string valueExpandable string value (REG_EXPAND_SZ)-Expandable string value  Hives  System-accessible only files containing registry database  Consist of a data file and a log file  Path- “%systemroot%\System32\config”

6. Windows Registry  Registry in Windows Boot Process 1.In the initial hardware detection phase, NTDETECT.COM detects the installed hardware, which information later will be stored in the HKEY_LOCAL MACHINE\HARDWARE key. 2.NTLDER then loads the information in the HKEY_LOCAL MACHINE\SYSTEM key, which contains the information regarding the device and service drivers that will be loaded. 3.NTLDR then creates the HKEY_LOCAL MACHINE\HARDWARE key and a Clone ControlSet key, which is a read-only copy of the ControlSet key created in step 2. 4.The boot process then initializes the drivers and services loaded earlier and records any errors in the Registry.

7. Windows Registry  Registry Security  Security is set by Registry permissions.  In Windows 2000, regedt32.exe must be used to set permissions. In Windows XP, regedit.exe can also be used.  Are two basic permission available ReadRead Full ControlFull Control  By default, only the System and Administrators have “full control” permissions  Can also create specific permissions  Inheritance behavior can be set to determine which permissions are inherited to child keys  Registry access can also be audited

8. Windows Registry  Registry Customization  Two native Windows Registry editors available  Regedt32.exe  Regedit.exe  While many books recommend using regedt32.exe as only it supports read-only mode and permissions (Windows 2000 only), regedit.exe is much easier to work with and is recommended for experienced Registry editors.  Can set certain keys as “Favorites” in regedit.exe  Can export keys to a text file (“regedit4” mode )

9. Windows Registry  Registry Customization  HKEY_CURRENT_USER  Control Panel  Software\{Various software apps}  Software\Microsoft  Software\Microsoft\Windows\Current Version  Software\Microsoft\Windows NT\Current Version  HKEY_LOCAL MACHINE  Software\Classes  Software\{Various software apps}  Software\Microsoft  Software\Microsoft\Windows\Current Version  Software\Microsoft\Windows NT\Current Version  System\CurrentControlSet

10. Windows Registry  Sources  Source for much of this presentation: Microsoft Windows 2000 Professional Installation and Configuration Handbook (Que Books)-Appendix A: The Registry and Registry Editors  Strongly recommend visiting http://www.winguides.com/registry/ as it has a collection of Registry books, Registry tips, and even a Registry tutorial http://www.winguides.com/registry/