Go to the following website:
unfortunately it does not translate very well from its native Russian, but a potted version of what you need to do is as follows:
1. Download the Casio QV-R40 firmware to a safe place on your PC, unzip it, and put a copy of the unzipped binary file onto a blank or spare SD card.
2. Insert the SD card in the camera, and then hold the Menu button pressed in while pressing the On/Off button.
3. A menu will appear on the screen saying Program Update, Yes/No
4. Select Yes and press the SET button.
5. After a short while you should get a message to say the update is complete. Switch off the camera and remove the SD card, and put in another SD card.
6. Switch on the camera, and hopefully it will restart as new. You will need to enter time-zone, date, time etc.
It has worked for me!