Here is an example on how to delete files in the file sytem:-

public static void DeleteFile(string FilePath)
    {
        try
        {
            FileInfo TheFile = new FileInfo(HttpContext.Current.Server.MapPath(FilePath));
            if (TheFile.Exists)
            {
                File.Delete(HttpContext.Current.Server.MapPath(FilePath));
            }
            else
            {
                throw new FileNotFoundException();
            }
        }
        catch (FileNotFoundException e)
        {
            LogEntry log = new LogEntry();
            log.EventId = 701;
            log.Message = "Error Deleting File\r\n" + FilePath + "\r\n" + e.ToString() + "\r\n" + e.StackTrace;
            log.Categories.Add("General");
            log.Severity = TraceEventType.Information;
            log.Priority = 5;
            Logger.Write(log);
        }
        catch (Exception e)
        {
            LogEntry log = new LogEntry();
            log.EventId = 1301;
            log.Message = "Error Deleting File Exception\r\n" + FilePath + "\r\n" + e.ToString() + "\r\n" + e.StackTrace;
            log.Categories.Add("General");
            log.Severity = TraceEventType.Information;
            log.Priority = 5;
            Logger.Write(log);
        }
 
    }

The example code above has some custom error exception handling that you may want to remove.