Can't figure this out

Can someone please help. The computer on my Scenic RX4 was showing flashing dashes. I got instructions from this forum on how to do a reset. However, over a few days it reverts back to the flashing dashes. I have done several resets, all with the same results. Even with the resets, it wasn't giving the fuel used and showing that I was getting 99.9 mpg, or giving estimated mileage until refuel. Is there another way of doing a reset. What if I were to dis-connect the battery, would that do something like a re-boot. Any help would be appreciated. Thanks