This function returns 0 if the key exists.
Code:
Const REG_SZ = 1 '
Const REG_BINARY = 3 ' Free form binary
Const HKEY_CURRENT_USER = &H80000001
Private Declare Function RegCloseKey Lib "advapi32.dll" (ByVal hKey As Long) As Long
Private Declare Function RegQueryValueEx Lib "advapi32.dll" Alias "RegQueryValueExA" (ByVal hKey As Long, ByVal lpValueName As String, ByVal lpReserved As Long, lpType As Long, lpData As Any, lpcbData As Long) As Long
Function RegQueryStringValue ByVal strValueName As String) As Long
Dim hKey as Long
Dim lResult As Long, lValueType As Long, strBuf As String, lDataBufSize As Long
hKey= HKEY_CURRENT_USER
'retrieve nformation about the key
RegQueryStringValue = _
RegQueryValueEx(hKey, strValueName, 0, lValueType, ByVal 0, lDataBufSize)
End Function