Only the Sodaq One V3 has a reset button.
The V1 and V2 have a user programmable button.
On the V1 and V2 you need to use the base board with reset button or wire the reset pin with a wire to ground twice.
In the device manager you can see if the reset worked. You have a different com port when you are in bootloader mode.
If you have an Atmel ICE you can also burn the boatloader again.