Difference between Regedit.exe & Regedit32.exe

1) Regedit.exe :

• It's a configuration editor for Windows XP and Windows Server 2003. 
• It 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 cannot view or edit all functions or data types on Windows NT 4.0 and Windows 2000.
• Limitation :
• cannot save or restore keys as hive files.
• cannot set the security for registry keys
• cannot view, edit, or search the value data types <>REG_EXPAND_SZ and <>REG_MULTI_SZ. If you try to view  it'll show binary data type
• Support importing and exporting registration entries (.reg) files.

 2) Regedt32.exe :

• It's a configuration editor for Windows NT 4.0 and Windows 2000.
• 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, where you change registry values. Incorrect values in the registry can make the Windows installation unusable.
• Not support importing and exporting registration entries (.reg) files.