Since NOOBS creates a RECOVERY partition to keep the original installation images, an 8 GB SD card or larger is recommended. You will also need an SD card reader (experience has shown that some built-in card readers can cause issues, so an external USB type reader is recommended).
If you are using an SD card that you have used previously, you may need to reformat it to remove any previous partitions and data. NOOBS expects the SD card to consist of a single FAT32 partition.
If using Windows or macOS X, you can use the SD Association's formatter, as shown in the following screenshot (available at https://www.sdcard.org/downloads/formatter_4/):
Getting rid of any partitions on the SD card, using SD formatter
From the Option Setting ...
