How to increase the processing time for the window service

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C#

VB

I have a window services (read data from excel file and save the results into the database).
In time, the program will read the data, other time it dont't read data. When it reading data, the program can read, but time of processing is too long, so services don't return any data at all.
I want to ask is there a way to increase the processing time for my service?
or create a console application,window form like window service?
my code with no errors at all.
I even split into 3 times reading and still not be

Protected Overrides Sub OnStart(ByVal args() As String)
        Me.RequestAdditionalTime(5000)
        Dim db As New Common.filelog()
        Try
           
            timeout = Configuration.ConfigurationManager.AppSettings("timeout")
            aTimer = New System.Timers.Timer(timeout)
            AddHandler aTimer.Elapsed, AddressOf OnTimedEvent
            aTimer.Interval = timeout
            aTimer.Enabled = True
            f = Configuration.ConfigurationManager.AppSettings("pathdc3")
            If Now.Hour <= 7 Then
                curr = Now.AddDays(-1)
            Else
                curr = Now
            End If
            f = f & "D" & format(curr.Month) & format(curr.Day) & curr.Year & ".xls"
         
        Catch ex As Exception
            
        End Try
    End Sub
Private Sub OnTimedEvent(ByVal source As Object, ByVal e As ElapsedEventArgs)
        Dim db As New Common.filelog()
        f = Configuration.ConfigurationManager.AppSettings("pathdc3")
        Dim fromminute As Integer = Configuration.ConfigurationManager.AppSettings("fromminute")
      
        If Now.Hour <= 7 Then
            curr = Now.AddDays(-1)
        Else
            curr = Now
        End If
        f = f & "D" & format(curr.Month) & format(curr.Day) & curr.Year & ".xls"
        If File.Exists(f) Then
                If Now.Minute = fromminute Or Now.Minute = fromminute + 30 Then
                Openfile(f)
                readproductNumber()
                Closefile(f)
                st &= Now & vbCrLf
                db.WriteLog(st & "Insert success P1!")
            End If
            If Now.Minute = fromminute + 2 Or Now.Minute = fromminute + 32 Then
                Openfile(f)
                readElectronic()
                Closefile(f)
                st &= Now & vbCrLf
                db.WriteLog(st & "Insert success P2!")
            End If
            If Now.Minute = fromminute + 4 Or Now.Minute = fromminute + 34 Then
                Openfile(f)
                readDaily()
                Closefile(f)
                st &= Now & vbCrLf
                db.WriteLog(st & " insert success P3!")
            End If
            st &= Now & vbCrLf
            db.WriteLog(st)
        Else
            st &= Now & vbCrLf
            db.WriteLog(st & "not found file " & f)
        End If

    End Sub