How do I convert a recording that plays on my laptop, but not on my satnav?

I wish to play a video recording that I made with my small airborne video camera. The recording plays okay on my laptop, but not on my Silvercrest PNA-M4310 Satnav. When i load in the SD card containing the film, it gives the readout that the card is overspec. I have been told that I need to convert the video into a format that can be read by the satnav, but I have no idea how to go about it. Can anyone help me.