>I want to log error information into a text file. In VFP I would do it with a simple STRTOFILE() function. Is there something like that in .NET?

This is what I use to create a file from a string:

        ' Create a file
        ' expC1 String
        ' expC2 File
        Public Function CreateFile(ByVal tcString As String, ByVal tcFile As String) As Boolean
            Dim llSuccess As Boolean = False
            Dim lnCounter As Integer = 0
            Dim lnDelay As Integer = 250
            Dim lnRetry As Integer = 8
            Dim loFileStream As FileStream
            Dim loStreamWriter As IO.StreamWriter
            For lnCounter = 1 To lnRetry
                Try
                    loFileStream = New FileStream(tcFile, FileMode.Create)
                    loStreamWriter = New StreamWriter(loFileStream, System.Text.Encoding.Default)
                    loStreamWriter.Write(tcString)
                    loStreamWriter.Close()
                    loFileStream.Close()
                    llSuccess = True
                    Exit For
                Catch loError As Exception

                    ' If we have not reached the maximum tries of 8, we retry
                    If lnCounter < 8 Then

                        ' Wait for a timeout before retrying
                        System.Threading.Thread.Sleep(lnDelay)

                        Continue For
                    End If

                    ' Get the proper definition as per the current scope
                    If oProcess Is Nothing Then
                        oApp.ErrorSetup(loError)
                    Else
                        oProcess.ErrorSetup(loError)
                    End If

                End Try
            Next
            Return llSuccess
        End Function

This one takes care of retrying in case it doesn't work. You will also need to adjust to Exception section to fit yours.