Can you add .wav to the 610 - Coby MP-610 MP3 Player

I do not know a whole lot about croatian letters and keyboard fixes for the Nokia 610, however, there may be some ways in the language settings of the settings menu, and if I remember right, there are some characters on the preset keyboard that you can hold down to get alternate characters. I hope this helps you, even if just a little.

Supported digital audio standards MP3 ,
WAV ,
WMA

OK well in that case you could convert them to WAV and join that and play it that way? Download and install the Switch Audio Converter. Switch can convert between numerous audio file types and has the capability of reading MSV files.
Add the MSV file you would like to convert to the Switch converter. Click on "Add File(s)" and browse for the file in the search window that comes up. When you locate the file, click "Open" to import it to the converter.
Select WAV as your output file type. The .wav extension is one of the options in the "Output Format" drop-down menu at the bottom-left corner of the Switch screen. Choose an output folder for your WAV file. To find a folder, click "Browse" next to the "Output folder" box. Locate the folder where you would like to save the WAV file on your hard drive and click "OK."

Click "Convert" to begin the conversion process. The "Convert" button is in the bottom-right corner of the screen. When you click "Convert," a small window with a progress bar will pop up to monitor the status, and a pop-up message will inform you when the conversion is complete. The WAV file will now be available in your chosen output folder. http://www.softplatz.com/freeware/wav-joiner/

http://download.cnet.com/Switch-Audio-Converter/3000-2140_4-10703967.html

Following these instructions for fixing your Coby Mp-610 MP3 Player will allow your computer to show the icon, and allow you to add music.

try this : go to control panel there click (add device ) . just follow the steps and problem will be solved .
good luck .

how to fix my coby mp3 player MP610-2g

The only way to add a wav of your own is by going into Start > Programs > File Explorer > click on 'my device' then the 'windows' folder cut and paste your wav file in this folder directly. This works as I've just had the same problem.

In order to use tones other than the presets for text messages, you have to put new .WAV files on your phone. Any 8bit .WAV file will work; just connect with ActiveSync and navigate to your /Windows directory on your phone, and place the files there. You will then be able to use them as text message alert tones.