Events of watcher wont work as planned for synchronization program?

Question

So I am having a synchronization program and I am using the filesystemwatcher to watch the changing in a directory. Now I had a listbox and I would add a different text at Changed, Created, Renamed and Deleted. Now what I noticed was, sometimes when I create a file it gives me the text:

"File has been created"

"File has been changed"

I read somewhere that the filesystemwatcher shouldn't be used cause the events are triggered when sometimes it shouldn't be.

Now I get this problem(I think it's because of the multiple events at once), When I drag a file in the directory I am watching, It should copy the file to the 2nd directory. If it already exists in the 2nd directory it should delete it and then copy it. Now I got the error:

The process cannot access the file because it is being used by another process

At the line where I delete the existing file in the 2nd directory. Now I was wondering wether the Filesystemwatcher is the problem here. Since it also triggers events and maybe it is still being "changed". which shouldn't have been triggered.

My question is:

Is the filesystemwatcher the problem?(So more like, is this a known problem?)

If so:

Is there something to replace the filewatcher with?

If not, this is my code + explanations of some variables:

Source = the first directory

target= the second directory

Record(); = executes readquery

postgresql(); = inserts in postgressql with the strSelectCmd (Has nothing to do with it)

        public static void copyfolder()
    {
        String source = ConfigurationManager.AppSettings[@"Directory1"];
        String target = ConfigurationManager.AppSettings[@"Directory2"];

        Copy(@source, @target);
    }

(string.IsNullOrEmpty(filename) == false) The actuall check if the file exists in the database.

 private void fileSystemWatcher1_Created(object sender, System.IO.FileSystemEventArgs e)
        {
            if (!pause)
            {
                logger("File created> " + e.FullPath + " -Date:" + DateTime.Now);
                filepath = Path.Combine(source, e.Name);
                name = Path.GetFileNameWithoutExtension(filepath);
                extension = Path.GetExtension(e.FullPath);
                size = e.Name.Length;
                strSelectCmd = "INSERT INTO" + tablepostgresql + " (" + column1 + "," + column2 + "," + column3 + "," + column4 + ") VALUES('" + name + "','" + size + "',now(),'" + extension + "')";
                readquery = "select * from " + tablemysql + " where name='" + name + "'";
                postgresql();
                Record();

                if (string.IsNullOrEmpty(filename) == false)
                {

                    if (Directory.Exists(e.FullPath))
                    {
                        copyfolder();
                        Directory.CreateDirectory(target);
                    }
                    else
                    {
                        if (WaitForFileAvailable(e.FullPath, TimeSpan.FromSeconds(30)))
                        {
                            var file = Path.Combine(source, e.Name);
                            var copy_file = Path.Combine(target, e.Name);
                            var destination = Path.Combine(target, Path.ChangeExtension(source, Path.GetExtension(source)));
                            if (File.Exists(copy_file))// Check to see if the file exists. 
                            {                     //If it does delete the file in the target and copy the one from the source to the target.
                                File.Delete(copy_file);
                            }
                            File.Copy(e.FullPath, copy_file);

                        }
                        else // The file failed to become available within 10 seconds.
                        {
                            logger("Copy has failed reason: File is being used by another program");
                        }

                    }
                }
                    if (demo == "yes")
                    {
                        query = "INSERT INTO " + tablemysql + " (name,size,last_edit,extension) VALUES('" + name + "','" + size + "',now(),'" + extension + "')";
                        Mysql();
                    }

            }
        }

The error appears at this line:

File.Delete(copy_file);