Windows NT-based operating systems include two utilities for editing the registry, Regedit.exe and Regedt32.exe. The following describes the differences between the two utilities for each Windows NT-based operating system.

• Windows NT 3.x
• Windows NT 4.0 and Windows 2000
• Windows XP and Windows Server 2003

Regedit.exe

Regedit.exe is the registration editor for 16-bit Windows. It is used to modify the Windows registration database. The database is located in the Windows directory as Reg.dat. The database contains information about 16-bit applications, and is used by File Manager for opening and printing files. It is also used by applications that support Object Linking and Embedding (OLE). Reg.dat is used and maintained by Windows on Windows (WOW) and 16-bit Windows applications. The WOW layer resides on top of the Virtual DOS Machine (VDM).

Regedit.exe is a 16-bit application that is included in Windows NT for compatibility with previous 16-bit applications. Regedit provides a method for examining Reg.dat under Windows NT. You can migrate the Reg.dat database file to the Windows NT registry during the first logon to an initial installation of Windows NT.

The Find tool in Registry Editor (Regedit.exe) searches for string values only. It is not able to locate data contained in a DWORD or Binary value.

To search for data contained in a DWORD or Binary value, you must first export the branch you want to search to a text file. Then, open the file in a text editor and use the editor's search tool to find the data.
NOTE: The Windows NT version of Regedit.exe is identical to the version in Windows 95.

To search for DWORD data (such as "0x1234abcd") or Binary data (such as "12 34 ab cd") using this technique, follow these steps:

1. Start Regedit.exe and click the HKEY_LOCAL_MACHINE branch.
2. On the Registry menu, click Export Registry File.
3. Type an arbitrary file name (for example, Hkey_lm.txt), and then verify that Save As Type is set to Registration Files and that Export Range is set to Selected Branch. Click Save.
   NOTE: Setting Export Range to All exports the entire registry to a text file, not just the selected branch.
4. Locate the text file and open it with any text editor (such as Notepad).
5. Use the text editor's search feature to find the data. The format of the text string depends on the data type (DWORD or Binary). For example, the sample binary value "12 34 ab cd" appears as "hex:12,34,ab,cd" and the sample DWORD value "0x1234abcd" appears as "dword:1234abcd."

Regedt32.exe

Regedt32.exe is the configuration editor for Windows NT. It is used to modify the Windows NT configuration database, or the Windows NT registry. This editor allows you to view or modify the Windows NT registry. The editor provides views of windows that represent sections of the registry, named hives. Each window displays two sections. On the left side, there are folders that represent registry keys. On the right side, there are the values associated with the selected registry key.

Regedt32 is a powerful tool. You must use extreme caution when you use it to change registry values. Missing or incorrect values in the registry can make the Windows NT installation unusable.

Regedit.exe

Regedit.exe is included with Windows NT 4.0 and Windows 2000 primarily for its search capability. You can use Regedit.exe to make changes in the Windows NT 4.0 and Windows 2000 registry, but you cannot use it to view or edit all functions or data types on Windows NT 4.0 and Windows 2000.

The following limitations exist in the Regedit.exe version that is included with Windows NT 4.0 and Windows 2000:

• You cannot set the security for registry keys.
• You cannot view, edit, or search the value data types REG_EXPAND_SZ and REG_MULTI_SZ. If you try to view a REG_EXPAND_SZ value, Regedit.exe displays it as a binary data type. If you try to edit either of these data types, Regedit.exe saves it as REG_SZ, and the data type no longer performs its intended function.
• You cannot save or restore keys as hive files.

Microsoft recommends that you use Regedit.exe only for its search capabilities on a Windows NT 4.0-based or Windows 2000-based computer.

The Find tool in Registry Editor (Regedit.exe) searches for string values only. It is not able to locate data contained in a DWORD or Binary value.

To search for data contained in a DWORD or Binary value, you must first export the branch you want to search to a text file. Then, open the file in a text editor and use the editor's search tool to find the data.
NOTE: The Windows NT version of Regedit.exe is identical to the version in Windows 95.

To search for DWORD data (such as "0x1234abcd") or Binary data (such as "12 34 ab cd") using this technique, follow these steps:

1. Start Regedit.exe and click the HKEY_LOCAL_MACHINE branch.
2. On the Registry menu, click Export Registry File.
3. Type an arbitrary file name (for example, Hkey_lm.txt), and then verify that Save As Type is set to Registration Files and that Export Range is set to Selected Branch. Click Save.
   NOTE: Setting Export Range to All exports the entire registry to a text file, not just the selected branch.
4. Locate the text file and open it with any text editor (such as Notepad).
5. Use the text editor's search feature to find the data. The format of the text string depends on the data type (DWORD or Binary). For example, the sample binary value "12 34 ab cd" appears as "hex:12,34,ab,cd" and the sample DWORD value "0x1234abcd" appears as "dword:1234abcd."

Regedt32.exe

Regedt32.exe is the configuration editor for Windows NT 4.0 and Windows 2000. Regedt32.exe is used to modify the Windows NT configuration database, or the Windows NT registry. This editor allows you to view or modify the Windows NT registry. The editor provides views of windows that represent sections of the registry, named hives. Each window displays two sections. On the left side, there are folders that represent registry keys. On the right side, there are the values associated with the selected registry key. Regedt32 is a powerful tool, and you must use it with extreme caution when you change registry values. Missing or incorrect values in the registry can make the Windows installation unusable.

Note Unlike Regedit.exe, Regedt32.exe does not support importing and exporting registration entries (.reg) files.

Regedit.exe

Regedit.exe is the configuration editor for Windows XP and Windows Server 2003. Regedit.exe is used to modify the Windows NT configuration database, or the Windows NT registry. This editor allows you to view or modify the Windows NT registry. It supports setting security on registry keys, viewing and editing REG_EXPAND_SZ and REG_MULTI_SZ, and saving and restoring hive files. On the left side, there are folders that represent registry keys. On the right side, there are the values associated with the selected registry key. Regedit is a powerful tool. You must use extreme caution when you use it to change registry values. Missing or incorrect values in the registry can make the Windows installation unusable.

Regedt32.exe

In Windows XP and Windows Server 2003, Regedt32.exe is a small program that just runs Regedit.exe.

The above information applies to:

• Microsoft Windows Server 2003, Standard Edition
• Microsoft Windows Server 2003, 64-Bit Datacenter Edition
• Microsoft Windows Server 2003, 64-Bit Enterprise Edition
• Microsoft Windows Server 2003, Web Edition
• Microsoft Windows Server 2003, Datacenter Edition
• Microsoft Windows Server 2003, Enterprise Edition
• Microsoft Windows XP 64-Bit Edition Version 2003
• Microsoft Windows Small Business Server 2003, Premium Edition
• Microsoft Windows Small Business Server 2003, Standard Edition
• Microsoft Windows XP Media Center Edition
• Microsoft Windows XP Professional
• Microsoft Windows XP Tablet PC Edition
• Microsoft Windows XP 64-Bit Edition Version 2002
• Microsoft Windows XP Home Edition
• Microsoft Windows 2000 Advanced Server
• Microsoft Windows 2000 Datacenter Server
• Microsoft Windows 2000 Professional
• Microsoft Windows 2000 Server
• Microsoft Windows NT Server 4.0
• Microsoft Windows NT Server 4.0 Terminal Server Edition
• Microsoft Windows NT Server, Enterprise Edition
• Microsoft Windows NT Workstation 4.0
• Microsoft Windows NT Workstation 3.5
• Microsoft Windows NT Workstation 3.51
• Microsoft Windows NT Server 3.5
• Microsoft Windows NT Server 3.51