>J'aimerai savoir comment faire pour que mon programme visual basic soit capable de déterminer si la configuration du système prend des . ou des , comme séparateurs de décimales.

Essai ce petit bout de code. En prime je t'offre le format de la date ainsi que le séparateur de la date.

Private Declare Function GetProfileString Lib "kernel32" Alias "GetProfileStringA" (ByVal lpAppName As String, ByVal lpKeyName As String, ByVal lpDefault As String, ByVal lpReturnedString As String, ByVal nSize As Long) As Long

Public Sub ChargerInfoReg()
Dim lngReturn As Long
Dim strDate As String
Dim strSepDate As String
Dim strSdecimal As String

strDate = String$(20, 0)
lngReturn = GetProfileString("INTL", "sShortDate", "DD/MM/YYYY", strDate, Len(strDate))
strDate = Left$(strDate, lngReturn)

strSepDate = String$(20, 0)
lngReturn = GetProfileString("INTL", "sDate", "/", strSepDate, Len(strSepDate))
strSepDate = Left$(strSepDate, lngReturn)

strSdecimal = String$(20, 0)
lngReturn = GetProfileString("INTL", "sDecimal", ".", strSdecimal, Len(strSdecimal))
strSDecimal = Left$(strSdecimal, lngReturn)
End Sub