[RESOLVED] Can't Read Timezones From Registry Unless Admin

[Hassan Basri]

Hello,

I have a VB6 program that lists the available timezones and populates a combobox. Similar to the timezone combobox in the "Date and Time Properties" of windows.

This is working fine in all versions of windows. I came upon a situation where my combobox was not being populated. After some investigation I found that the program didn't have access to this path in the registry:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones

When I run the program as an admin the combobox gets populated correctly. If I run as the regular user the combobox doesn't get populated. My program writes and reads to its own folder in the regsitry without issue. However unless I am admin on this particular machine I can't read this path

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones

Any ideas anybody? Thanks.

[Nightwalker83]

Retrieve a list of Timezones using vb6.

[Hassan Basri]

Thanks for the answer. I am already doing that but for some reason this is not working. RegOpenKeyEx fails on this machine unless I run the application with admin permissions. Here is my full function PopulateTimeZones. Let me know if you see anything that could fix this issue. Thanks.

Private Function PopulateTimezones(Optional blnFindMatch As Boolean, Optional strTimezone As String) As String

Dim sKeyValue As String
Dim sValue As String
Dim lResult As Long
Dim lIndex As Long
Dim hKeyMain As Long
Dim hKey As Long
Dim lType As Long
Dim sName As String
Dim lngLengthStd As Long
Dim lngLengthDisplay As Long

Dim lngResultStd As Long
Dim lngResultDisplay As Long

Dim arrTimezones() As String
Dim iCounter As Integer

On Error GoTo ErrorHandler

CurrentValue = ""

If m_lngWindowsVersion = VER_PLATFORM_WIN32_WINDOWS Then
    strSubKey = SKEY_9X
Else
    strSubKey = SKEY_NT
End If

ReDim arrTimezones(0)

lResult = RegOpenKeyEx(HKEY_LOCAL_MACHINE, strSubKey, 0, KEY_ALL_ACCESS, hKeyMain)

If lResult = ERROR_SUCCESS Then
    lIndex = 0
    Do
        lngLengthStd = 32
        sKeyValue = String(lngLengthStd, 0)
        lResult = RegEnumKey(hKeyMain, lIndex, sKeyValue, lngLengthStd)
        
        If lResult = ERROR_SUCCESS Then
        
            ''''''''''''''''''''''''''''''''''''''''
            lngResultDisplay = RegOpenKeyEx(HKEY_LOCAL_MACHINE, strSubKey & "\" & sKeyValue, 0, KEY_ALL_ACCESS, hKey)
            lngResultDisplay = RegQueryValueEx(hKey, "Display", 0&, lType, ByVal 0&, lngLengthStd)
            sValue = Space(lngLengthStd - 1)
            lngResultDisplay = RegQueryValueEx(hKey, "Display", 0&, lType, ByVal sValue, lngLengthStd)
            RegCloseKey hKey
            ''''''''''''''''''''''''''''''''''''''''
            lngResultStd = RegOpenKeyEx(HKEY_LOCAL_MACHINE, strSubKey & "\" & sKeyValue, 0, KEY_ALL_ACCESS, hKey)
            lngResultStd = RegQueryValueEx(hKey, "Std", 0&, lType, ByVal 0&, lngLengthDisplay)
            sName = Space(lngLengthDisplay - 1)
            lngResultStd = RegQueryValueEx(hKey, "Std", 0&, lType, ByVal sName, lngLengthDisplay)
            RegCloseKey hKey
            ''''''''''''''''''''''''''''''''''''''''
            If (lngResultDisplay = ERROR_SUCCESS) And (lngResultStd = ERROR_SUCCESS) Then
                If Not blnFindMatch Then
                    ReDim Preserve arrTimezones(lIndex)
                    arrTimezones(lIndex) = Trim$(Left$(sValue, lngLengthStd))
                    
                    If CurrentTimezone = Trim$(Left$(sName, lngLengthDisplay)) Then
                        CurrentValue = Left$(sValue, lngLengthStd)
                    End If
                ElseIf sValue = strTimezone Then
                    PopulateTimezones = sKeyValue
                    RegCloseKey hKeyMain
                    Exit Function
                End If
            End If
            
        End If
        lIndex = lIndex + 1
    Loop While lResult = ERROR_SUCCESS
    RegCloseKey hKeyMain
    
    '''''''''''''''''''''''''''''''''''''''''''''''
    Call SortArray(arrTimezones)
    For iCounter = 0 To UBound(arrTimezones)
        If arrTimezones(iCounter) <> "" Then
            cboWindowsTimezone.AddItem arrTimezones(iCounter)
        End If
    Next iCounter
Else
    MsgBox "Error"
    PopulateTimezones = ""
End If

Exit Function
ErrorHandler:
PopulateTimezones = ""

End Function

[dilettante]

Have you tried asking for less (read only) access?

[Hassan Basri]

Have you tried asking for less (read only) access?

Thanks dilettante. That did it. I changed KEY_ALL_ACCESS to KEY_READ and it now works.

Thanks again.

For those who need KEY_READ it is as follows:

Public Const READ_CONTROL As Long = &H20000
Public Const STANDARD_RIGHTS_READ As Long = (READ_CONTROL)
Public Const KEY_READ = ((STANDARD_RIGHTS_READ Or KEY_QUERY_VALUE Or KEY_ENUMERATE_SUB_KEYS Or KEY_NOTIFY) And (Not SYNCHRONIZE))