Sony has released the 3.21 PS3 firmware update. The mandatory update removes the ‘Install Other OS’ function from older PS3s, and warns users that it will be taking away the feature. If you don’t download and install the update, you won’t be able to use any aspects of the PlayStation Network. PS3s should prompt the update when they’re turned on, but you can also download the firmware online and install on a USB hard/flash drive.