How to create Registry key if it does not exists?

In one of my previous post, I posted about how to read and modify the Registry Settings using VBScript/QTP. But, this only works if Registry Key/SubKey (that you intends to read/modify) already exists.

In this post, first we will look at the small overview of what a Registry is and then we will look into, how to create Registry Key/SubKey and set the value if it does not exists.

Registry Overview:

The Windows Registry is a hierarchical database that stores configuration settings and options on Microsoft Windows operating systems. It contains settings for low-level operating system components and for applications running on the platform that have opted to use the registry. The registry contains two basic elements: keys and values. Registry keys are container objects similar to folders. Registry values are non-container objects similar to files. Keys may contain values or further keys (aka subkey). The hierarchy of registry keys can only be accessed from a known root key handle. There are seven predefined root keys, traditionally named according to their constant handles defined in the Win32 API:

•     HKEY_LOCAL_MACHINE
•     HKEY_CURRENT_CONFIG (only in Windows 9x/Me and NT-based Windows versions)
•     HKEY_CLASSES_ROOT
•     HKEY_CURRENT_USER
•     HKEY_USERS
•     HKEY_PERFORMANCE_DATA (only in NT-based Windows versions (but invisible))
•     HKEY_DYN_DATA (only in Windows 9x/Me, and visible in Windows Registry Editor)

How to create Registry Key/SubKey:

There are 2 methods to do this that I am going to post it here:

1) Using VBScript:

Dim objShell, RegLocate

'create windows shell object

Set objshell =CreateObject("WScript.Shell")

'Suppose New Windows and PopupMgr SubKey does not exists in the below Registry Path
RegLocate ="HKCU\Software\Microsoft\Internet Explorer\New Windows\PopupMgr"

'Reading Registry will throw an error if path doesn't exists

On Error Resume Next
reg_value=objshell.RegRead (RegLocate)
Err_Number=err.number
On Error Goto 0

'check for the error and then write the value to Registry
If err_number <> 0 Then
objShell.RegWrite RegLocate,"No","REG_SZ"
End If

Set objshell = Nothing

2) Using WMI:

Using methods of StdRegProv Class. You can find all the methods on the following link:

http://msdn.microsoft.com/en-us/library/aa393664%28v=vs.85%29.aspx

Here, I am using GetDWordValue, CreateKey and SetDWORDValue methods of StdRegProv class

Const HKEY_CLASSES_ROOT = &H80000000
Const HKEY_CURRENT_USER = &H80000001
Const HKEY_LOCAL_MACHINE = &H80000002
Const HKEY_USERS = &H80000003
Const HKEY_CURRENT_CONFIG = &H80000005

strComputer = "."

Set objRegistry = GetObject("winmgmts:\\" & strComputer & "\root\default:StdRegProv")

strKeyPath = "Software\Microsoft\Internet Explorer\New Windows"
strValueName = "PopupMgr"

'storing the value of strValueName from strKeyPath in dwValue
objRegistry.GetDWORDValue HKEY_CURRENT_USER,strKeyPath,strValueName,dwValue

'checking if Registry Key Exists
If cstr(IsNull(dwValue))="True" or cstr(objRegistry.EnumKey(HKEY_CURRENT_USER,strKeyPath,arrSubKeys)) <> "0" Then

msgbox "The registry key does not exist."

'setting 1 for strValueName in strKeyPath
objRegistry.SetDWORDValue HKEY_CURRENT_USER,strKeyPath,strValueName,1

objRegistry.GetDWORDValue HKEY_CURRENT_USER,strKeyPath,strValueName,dwValue

'checking if Registry Key still exists
If cstr(IsNull(dwValue))="True" Then

'If Registry Key still doesn't exists, then it means strKeyPath does not exist, need to create key first
objRegistry.CreateKey HKEY_CURRENT_USER,strKeyPath
objRegistry.SetDWORDValue HKEY_CURRENT_USER,strKeyPath,strValueName,1
objRegistry.GetDWORDValue HKEY_CURRENT_USER,strKeyPath,strValueName,dwValue
msgbox dwValue
Else
msgbox "The registry key exists."
End If
Else
msgbox "The registry key exists."
End If

Tip: If RegLocate terminates with “\”, then it is treated as Key, otherwise it is treated as Value