What if you have a corrupted SD or you would like to reburn an image to an SD Card previously used on your Pi? well then you probably would like to reformat it to make it clean again. In Windows this can be a bit tricky because once used for the Pi it will likely show Windows that you have a smaller SD card than is actually the case. Have no fear this is normal! Windows tries to only touch what it knows and since only a tiny portion of the SD card is left that Windows can recognize it leaves the “Linux Partition” alone. For this we use a program made by the people that create the standards for SD Cards “The SD Association” visit this link for the reformat tool https://www.sdcard.org/downloads/formatter_4/eula_windows/ scroll to the bottom accept the terms and once you install this tool you will be able to recover the lost space and reuse your SD again and again.