.RegWrite

Write a value to the Registry

Syntax 
 objShell.RegWrite strRegName, anyValue, [strType]
Arguments:
 objShell A WScript.Shell object
 strRegName 
 To set a key instead of a value terminate strRegName 
 with a backslash character \
 strRegName must start with one of
 HKEY_CURRENT_USER or HKCU
 HKEY_USERS 
 HKEY_LOCAL_MACHINE or HKLM
 HKEY_CLASSES_ROOT or HKCR
 HKEY_CURRENT_CONFIG
 strType
 The data type, one of:
 REG_SZ, REG_EXPAND_SZ, (String values)
 REG_DWORD (convert to Integer value)
 REG_BINARY (Integer value)

When you specify a key-name (as opposed to a value-name), RegRead returns the default value.

Examples

Set the registry flag to display Hidden and System files in Windows Explorer:

Set WshShell = CreateObject("WScript.Shell")
myKey = "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Hidden"
WshShell.RegWrite myKey,1,"REG_DWORD"

Set the registry flag to hide Hidden and System files in Windows Explorer (the default)

Set WshShell = CreateObject("WScript.Shell")
myKey = "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Hidden"
WshShell.RegWrite myKey,0,"REG_DWORD"

Create a "default value" at HKCU\KeyName\ n.b. the trailing backslash is required:

Set WshShell = WScript.CreateObject("WScript.Shell")
WshShell.RegWrite "HKCU\KeyName\","", "REG_SZ"

"Nothing is permanent" ~ Buddha

Related VBScript commands

Registry, delete - WshShell.RegDelete
Registry, read - WshShell.RegRead
Q281309 - Unable to Use a "\" in a Key Name with RegWrite.
Equivalent Windows CMD command: REG - Read, Set or Delete registry keys and values.
Equivalent PowerShell cmdlet: Set-Item