Some MP3 files that play fine on my computer can't be used as ringtones etc when copied to the phone. They play in the media player on the phone normally though.

MP3 players can only play music files in mp3 file format.
You can download mp3 music files from the Internet to your computer and then copy them to your MP3 player using the USB cable.
For your CD collection, you need to convert your CDs to mp3 music files onto your computer or download them from the Internet and then copy them to your MP3 player after you have connected the USB cable to the MP3 player and the computer.
You can do this using Windows Media player and Rip the CDs - Media Player will create a MP3 music file for each music track.
Click on this link for instruction on converting music files to mp3 file format :-

http://www.fixya.com/support/r5798418-creating_transferring_mp3_music_files

Check the specification of your MP3 player to determine the type of video file format it uses. Most common video files that MP3 players use are, AVI and WMV, there may be others such as FLV, MOV and DivX. If your player cannot play a video then it is an incompatible video file format, then you need to convert that video file to a format that your MP3 player uses. After video conversion then copy the video files to your MP3 player using the USB cable from your computer. Click on this link for instructions on converting video files for MP3 players :- http://www.fixya.com/support/r5874192-play_videos_mp3_player MP3 players can only play music files in mp3 file format. You can download mp3 music files from the Internet to your computer and then copy them to your MP3 player using the USB cable. For your CD collection, you need to convert your CDs to mp3 music files onto your computer or download them from the Internet and then copy them to your MP3 player after you have connected the USB cable to the MP3 player and the computer.
You can do this using Windows Media player and Rip the CDs - Media Player will create a MP3 music file for each music track. Click on this link for instruction on converting music files to mp3 file format :- http://www.fixya.com/support/r5798418-creating_transferring_mp3_music_files

MP3 players can only play music files in mp3 file format. You can download mp3 music files from the Internet to your computer and then copy them to your MP3 player using the USB cable. For your CD collection, you need to convert your CDs to mp3 music files onto your computer or download them from the Internet and then copy them to your MP3 player after you have connected the USB cable to the MP3 player and the computer.
You can do this using Windows Media player and Rip the CDs - Media Player will create a MP3 music file for each music track. Click on this link for instruction on converting music files to mp3 file format :- http://www.fixya.com/support/r5798418-creating_transferring_mp3_music_files

MP3 players can only play music files in mp3 file format.You can download mp3 music files from the Internet toyour computer and then copy them to your MP3 player using the USB cable.For your CD collection, you need to convert your CDs tomp3 music files onto your computer or download them from the Internet and thencopy them to your MP3 player after you have connected the USB cable tothe MP3 player and the computer.
You can do this using Windows Media player and Rip the CDs - Media Player willcreate a MP3 music file for each music track.Click on this link for instruction on converting musicfiles to mp3 file format :- http://www.fixya.com/support/r5798418-creating_transferring_mp3_music_files

The Itune music files maybe in MP4 file format.
MP3 players can only play music files in mp3 file format.You can download mp3 music files from the Internet toyour computer and then copy them to your MP3 player using the USB cable.For your CD collection, you need to convert your CDs tomp3 music files onto your computer or download them from the Internet and thencopy them to your MP3 player after you have connected the USB cable tothe MP3 player and the computer.
You can do this using Windows Media player and Rip the CDs - Media Player willcreate a MP3 music file for each music track.Click on this link for instruction on converting musicfiles to mp3 file format :- http://www.fixya.com/support/r5798418-creating_transferring_mp3_music_files

Most MP3 players do not play games.
MP3 players can only play music files in mp3 file format.You can download mp3 music files from the Internet toyour computer and then copy them to your MP3 player.For your CD collection, you need to convert your CDs tomp3 music files onto your computer or download them from the Internet and thencopy them to your MP3 player after you have connected the USB cable tothe MP3 player and the computer.
You can do this using Windows Media player and Rip the CDs - Media Player willcreate a MP3 music file for each music track.Click on this link for instruction on converting musicfiles to mp3 file format :- http://www.fixya.com/support/r5798418-creating_transferring_mp3_music_files

MP3 players can only play music files in mp3 file format.You can download mp3 music files from the Internet toyour computer and then copy them to your MP3 player.For your CD collection, you need to convert your CDs tomp3 music files onto your computer or download them from the Internet and thencopy them to your MP3 player after you have connected the USB cable tothe MP3 player and the computer.
You can do this using Windows Media player and Rip the CDs - Media Player willcreate a MP3 music file for each music track.Click on this link for instruction on converting musicfiles to mp3 file format :- http://www.fixya.com/support/r5798418-creating_transferring_mp3_music_files

Use Windows Media Player

The instructions in these pages, which are largely links, pertain to Windows Media Player 10 and 11 only.

Windows Media Player is made by Microsoft. The general help page for Windows Media Player is:

http://www.microsoft.com/windows/windowsmedia/default.mspx

Through this link, you can enter a variety of search terms that will help you find what you are looking for (exs.: “add files to my mp3 player”; “delete files from my mp3 player,” etc.)

Important Vocabulary:

The code word for “mp3 player” in Windows Media Player is “DEVICE” or “portable device”

The code word for adding files is “SYNC,” “syncing,” or “synchronizing”

The code word for copying files from CD is “RIP,” or “ripping”

The code word for files stored on both My Computer and my Mp3 player (when it is connected to the computer) is “LIBRARY”

To add files (SYNC) to your mp3 player using Windows Media Player 10:

http://www.microsoft.com/windowsxp/using/windowsmediaplayer/wmp10/harrison_wmp10.mspx

To add files (SYNC) to your mp3 player using Windows Media Player 11:

http://www.microsoft.com/windows/windowsmedia/player/faq/sync.mspx

To delete files from your mp3 player using Windows Media Player 10:

http://www.microsoft.com/windows/windowsmedia/knowledgecenter/mediaadvice/0085.mspx#EDF

To delete files from your mp3 player using Windows Media Player 11:

My Directions:

1. Connect your mp3 player to the computer

2. Open Windows Media Player

3. Click on the icon of your Mp3 player on the left-hand side of the Library

4. Click on the Songs, Tracks, or other Music Folder

5. Find a song or songs that you want to delete

6. Left-click the song once to highlight it

7. Press the “Delete” button on your computer’s keyboard

To copy (RIP) files from CD to Mp3 player using Windows Media Player 10:

http://www.microsoft.com/windowsxp/using/windowsmediaplayer/getstarted/ripcd.mspx

To copy (RIP) files from CD to Mp3 player using Windows Media Player 11:

http://www.microsoft.com/windows/windowsmedia/knowledgecenter/easystart/mp11guide.aspx#RippingCopySsongsfromCDstoYyourCcomputer

Use Windows Media Player to delete:

The instructions in these pages, which are largely links, pertain to Windows Media Player 10 and 11 only.

Windows Media Player is made by Microsoft. The general help page for Windows Media Player is:

http://www.microsoft.com/windows/windowsmedia/default.mspx

Through this link, you can enter a variety of search terms that will help you find what you are looking for (exs.: “add files to my mp3 player”; “delete files from my mp3 player,” etc.)

Important Vocabulary:

The code word for “mp3 player” in Windows Media Player is “DEVICE” or “portable device”

The code word for adding files is “SYNC,” “syncing,” or “synchronizing”

The code word for copying files from CD is “RIP,” or “ripping”

The code word for files stored on both My Computer and my Mp3 player (when it is connected to the computer) is “LIBRARY”

To add files (SYNC) to your mp3 player using Windows Media Player 10:

http://www.microsoft.com/windowsxp/using/windowsmediaplayer/wmp10/harrison_wmp10.mspx

To add files (SYNC) to your mp3 player using Windows Media Player 11:

http://www.microsoft.com/windows/windowsmedia/player/faq/sync.mspx

To delete files from your mp3 player using Windows Media Player 10:

http://www.microsoft.com/windows/windowsmedia/knowledgecenter/mediaadvice/0085.mspx#EDF

To delete files from your mp3 player using Windows Media Player 11:

My Directions:

1. Connect your mp3 player to the computer

2. Open Windows Media Player

3. Click on the icon of your Mp3 player on the left-hand side of the Library

4. Click on the Songs, Tracks, or other Music Folder

5. Find a song or songs that you want to delete

6. Left-click the song once to highlight it

7. Press the “Delete” button on your computer’s keyboard

To copy (RIP) files from CD to Mp3 player using Windows Media Player 10:

http://www.microsoft.com/windowsxp/using/windowsmediaplayer/getstarted/ripcd.mspx

To copy (RIP) files from CD to Mp3 player using Windows Media Player 11:

http://www.microsoft.com/windows/windowsmedia/knowledgecenter/easystart/mp11guide.aspx#RippingCopySsongsfromCDstoYyourCcomputer

Just copy the ringtone in phone memory which you want to set. It will give you option to set it as ringtone.