Well, you won't lose whatever is left. The BB will automatically start to delete stuff when it runs out of device memory.
Originally Posted by mayte
it shows 0 bytes on file free. Would this be effecting some slow downloads?App memory is 0,devicememory is 859 mb,free space 856 mb. Do I need a memory card? How big a one?
There's no such thing as "too much space". It applies to RAM. It applies to hard drives. And it applies to media cards. You probably do need a media card. Make sure you move all media (photos, ringtones, music, videos, etc) to the media card. The media card does not increase your device memory. It only gives you a place to store media files so they don't use up your device memory.