Вот скрипт на VBS
Код:

Const HKEY_CURRENT_USER = &H80000001
strComputer = "."
Set oReg=GetObject("winmgmts:{impersonationLevel=impersonate}!\\" & strComputer & "\root\default:StdRegProv")
strKeyPath = "Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced"
strValueName = "HideFileExt"
oReg.GetDWORDValue HKEY_CURRENT_USER,strKeyPath,strValueName,dwValue
If dwValue = 0 Then
dwValue = 1
oReg.SetDWORDValue HKEY_CURRENT_USER,strKeyPath,strValueName,dwValue
Else
dwValue = 0
oReg.SetDWORDValue HKEY_CURRENT_USER,strKeyPath,strValueName,dwValue
End If