Has it plugged in to USB to charge, disconnected it to play radio get error message Profiling need 4MB free space, and then it shutsdownI am not downloading anything I just want to play my radio,...what is the process?

Unplug the mp3 from the USB
press and hold the menu button for 10 seconds
release then press and hold the play button
-- while holding the play button plug it back in. Wait until it says intializing, then release the play button and press start.

Restoring RCA M4304A Recorder Firmware

Symtom: recorder shows OPAL splash screen, then shows "profiling requires20mb of free space, shutting down" and then shuts down. Recorder cannot be accessed by windows or the RCA easyrip software.

Solution: Use the firmware update found here: http://www.voxxsupport.com/images/downloads/OPAL_066F_85A4_85A5_0_1140_SIG.EXE

This update needs to be ran on an xp computer running 32 bitOS. It was tested in a Win 7 64bitmachine and proven to not work.

Necessary steps taken to get the firmware to properlyrestore were as follows:

1. Hold in the power (menu) button for 10 seconds(the splash screen will show and it will give the error message, ignore it)

2. While still holding the power button, press theplay/pause button and hold down.

3. Release the power button while still holdingdown the play/pause button and wait 5 seconds.

4. While still holding the play/pause button plugin the usb cable to the recorder. Continue to hold the play/pause button foranother 5 seconds after plugging the cable in.

5. Release the play pause button then launch theEXE for the firmware update. Minimize the instruction screen so you can see thefull update screen.

6. Leave the format checkbox checked (check it ifit isn't checked) formatting is crucial to this working.

7. Once the status in the update window changesfrom initializing to ready click start to update the recorder. It will go through formatting, then updating.

8. Once the status shows complete disconnect therecorder and with any luck the recorder is usable again. The media files will obviously have to bereloaded, but the recording is functional at least.

it says profiling requires 20mb free space

I couldn't find any software for you.But I did find a firmware update to reset the player to factory.You can always try that first and see what happens.
RCA Firmware Update

1. Disconnect the player.

2. Download the new driver from http://support.rcaaudiovideo.com/

3. Install the software on your computer, then run it.

4. Reset your player by either pressing the reset button or removing the AA-battery from the player.

5. While holding down the "Play" key on your player, connect it to the PC via the USB cable. Release the "Play" key when you see the progress bar moving and "initializing" text. If you cannot see the "initializing" text, please disconnect your player and try again.

6. Click the "Start" button to upgrade your player

Straiten the end of a paperclip and push it into the reset hole on the back. When you turn it on, it should operate as normal without any data loss.

Found a small pinhole on the back of the device. In small lettering it says reset. Carefully insert a pin and light push when you feel it's hit a dead end. It resets the issue and you can resume using your device. Leave it up to a girl to find that and figure it out. lol

same thing happend to me no clue how to fix

I have the same problem, and the RCA website is a piece of ****.

it probably means 4mb to show the screen so delete somthing off it and try