ok, first, when you buy a batterie(of you will need a second one in the future), wait until your tama has the ''X'' on the screen(this may be in atleast two months if you had a fresh batterie). if it still has the ''X'' on the screen, then the batterie is still usefull for a couple of weeks. then carefully remove the battery from the back of your tamagotchi. place the same battery you took out, inside the tamagotchi. carefully put the cover back on your tamagotchy and screw it in again. you will see an egg. press the ''B'' button when you see the egg. it will say ''down-load'' or ''restart'' click download. if your tamagotchi batterie dies again, keep doing this until the screen is blank, when it is, use the spare batterie. i hope this tip was usefull. please reply back if you like!