I have copied some files it is not visible in music folder

Use a USB card reader.

You cannot delete existing mp3 files/directories directly from the player but it is possible from the computer. Connect your mp3 player to a PC using the USB cable. It should become visible as a mounted removable drive.

If you can't see it, go to settings -> system and switch the UMS mode at the bottom of the list so it can become visible.

You should be able to see the drive in windows explorer and on Windows, you may even be asked as the drive connects if you want to view files,

Simply go to the directory structure, click through to music and delete files/folders that you no longer want. You can copy over new files from wherever you store your music, too. It's the same connection/viewing process.

Use a USB card reader attached to your computer

Before answering this, keep the following in mind about uploading files to your phone:
MP3 would be my personal choice for the phone you have. Since you are using Windows Media Player (WMP) on your PC, I assume that any music you have ripped with it would be in WMA format, or maybe WAV. WAV is compatible with your phone, but I haven't tried WMA.
Get into the folder the files for the player are stored in (usually My Music), and look at the format by right clicking and selecting properties. If the file format is not compatible with your phone, you can try changing the file extension by opening any folder, selecting tools>folder options>view, and then unclick "hide known file extensions." Then go back to the file and rename it, but only change the file extension. Example: if the file is named "music.wma", the you would change it to "music.mp3." This usually works with common audio files.
To answer your main question, the easiest way is to bypass all the media player ****, and go straight to the file folder where you music is stored in your "My Music" folder.
The following will work with a mini SD card too.
First connect your phone to your computer via a USB cable. A folder options box should come up. Choose to open the folder and explore files. It may not say exactly that, but you'll sort it out I'm sure. Find the "audio" folder inside the phone, and open it.
Then in your computer's music files, find the folder containing the music you want to put on your phone (usually "My Music"), right click the music file you want and select "copy". Go back to the folder for your phone or card, and copy the file into it. That's it.
There are many ways to copy the files with this method, but this one is the easiest to explain. You can copy entire folders to your phone, if you have enough memory. Also, ripped CD folders often contain album art, so I recommend selecting the files you want to copy, rather than the whole folder. Holding Ctrl while highlighting the files you want to copy will enable you to select multiple files and copy them all at once.

1. Have the "View Hidden Files and Folders" option enabled. To view them go to my documents and then tools>folder options>view. Then click the "Show hidden files and folders" under the "Hidden files and folders" section. (You will not have to scroll down the list to see it)
2. Plug the iPod into the computer that you wish to back it up on.
3. Open up a Windows Explorer Window, from the accessories folder of the programs listing.
4. Navigate to the "My Computer" icon.
5. Expand the folder, and find the drive that has the name of your iPod.
6. Expand your iPod's folder, and find the folder: "iPod Control".
7. Expand "iPod Control" and find the folder "Music".
8. Look for a series of folders with strange names.
9. Select all of the files. Do this by going to: Edit>Select All>. Alternatively, you may hold the Control key and click all of the folders.
10. Copy all of the folders, by going to Edit>Copy or by right clicking one of the selected folders and clicking copy. This will copy all of the folders.
11. Paste the music in the desired folder by using Edit>Paste.
12. Open each folder, and copy the MP3 files into the desired folder, or you can leave them where they are. The music will have non understandable names, like "EDCI" and "DLXE", 4 letter names are normal.
13. Open the music up in the music player of your choice if you wish. Do this when all of the music has been extracted from the original iPod folders.

• TIPS
• Most music player programs can decode the names into the original names, and artists.
• This works on both PCs and Macs, but these instructions are for PCs. Mac computers work similarly to this.
• The copying of the music takes some time.
• This can be used to copy friend's music.
• Get a good MP3-Tagger-Program e.g. mp3tag (freeware) and automatically rename the files if you want to use them on your PC
• WARNING
• Do not try and manually rename each song.
• Do NOT mess around with any other file(s) on the iPod
• Do not remove any songs from the list

have you tried going to the folder where the music is, selecting the tracks you want to copy then select edit>copy to folder then select the memry stick and click ok.
should work

Make sure the player is OFF before you plug it in and while you transfer you music or charging. Sounds odd but that is it in a nut shell. But here is step by step:

In essence it is as easy as copying files from one folder on your computer into the other.


1. Make sure your player is turned “OFF”.

Important Note: Having player “ON” when plugging and unplugging from computer may delete all files on the player.


2. Connect your player to any USB port on your computer via provided USB cable.


3. Computer will find it as a removable external hard drive.



4. Double click this drive to open it.


5. Open your music/video/text/image files folder in another window.


6. “Drag-and-Drop” your files from your directory on the computer to the root directory of the player.



7. Once the files are copied – disconnect the player from computer.


8. Turn KEO "ON" and go to the desired Mode ("Music", "Movie", etc..) Your newly-copied files should be visible there among other media files preloaded on the player. Use arrow buttons to scroll through them.


IMPORTANT NOTE!
Avoid creating separate folders for every 2-3 songs. Preferably put all audio files in he same “MUSIC” folder, or sort them by "Artist Names" folders or just store all in the root directory (do the same with VIDEO files).
KEO does not support playlists at this time and excessive amount of 2-3 levels of folders may noticeably slow down the operational speed of the unit.

if you you use realplayer you can import all the files off of it.
as far is i know this only works with music files not video or music that are non plus.
make sure that when you import the files that you are importing as mp3.

there are lots of different programs that do just that, the trick is to find one that works well and is free. best bet is to just google music from ipod and see what you can get.