Hi,
Refer below code.
https://docs.microsoft.com/en-us/previous-versions/sql/sql-server-2005/ms162139%28v=sql.90%29
C#
protected void StopSQL(object sender, EventArgs e)
{
    ManagedComputer mc = new ManagedComputer();
    Service svc;
    svc = mc.Services("MSSQLSERVER");
    if (svc.ServiceState == ServiceState.Running)
    {
        svc.Stop();
        Response.Write(string.Format("{0} service state is {1}", svc.Name, svc.ServiceState));
        while (string.Format("{0}", svc.ServiceState) != "Stopped")
        {
            Response.Write(string.Format("{0}", svc.ServiceState));
            svc.Refresh();
        }
        Response.Write(string.Format("{0} service state is {1}", svc.Name, svc.ServiceState));
        svc.Start();
        while (string.Format("{0}", svc.ServiceState) != "Running")
        {
            Response.Write(string.Format("{0}", svc.ServiceState));
            svc.Refresh();
        }
        Response.Write(string.Format("{0} service state is {1}", svc.Name, svc.ServiceState));
    }
    else
    {
        Response.Write("SQL Server service is not running.");
    }
}
VB.Net
Protected Sub StopSQL(ByVal sender As Object, ByVal e As EventArgs)
    Dim mc As ManagedComputer = New ManagedComputer()
    Dim svc As Service
    For Each svc In mc.Services
        Response.Write(svc.Name)
    Next
    svc = mc.Services("MSSQLSERVER")
    If svc.ServiceState = ServiceState.Running Then
        svc.Stop()
        Response.Write(String.Format("{0} service state is {1}", svc.Name, svc.ServiceState))
        Do Until String.Format("{0}", svc.ServiceState) = "Stopped"
            Response.Write(String.Format("{0}", svc.ServiceState))
            svc.Refresh()
        Loop
        Response.Write(String.Format("{0} service state is {1}", svc.Name, svc.ServiceState))
        svc.Start()
        Do Until String.Format("{0}", svc.ServiceState) = "Running"
            Response.Write(String.Format("{0}", svc.ServiceState))
            svc.Refresh()
        Loop
        Response.Write(String.Format("{0} service state is {1}", svc.Name, svc.ServiceState))
    Else
        Response.Write("SQL Server service is not running.")
    End If
End Sub