A:Answer Thanks Dee.
You wouldn't exactly "expand" a card. If you want to store more than the original card, you would need to buy a new, larger card. However, if you mean once the card is full, how do you keep recording, the system can overwrite the older footage to keep recording. If you want to see it on the computer or delete the footage there, you can take the SD card out of the monitor and put it in your computer, it would need a card reader which is built into some computers and most laptops, but you can get a USB adapter if not.