I bought an 8gb card, used SD formatter and turned size adjustment (I think that's what it's called?) on. It reduced the size by a gigabyte or so. Windows disk management and everything else in windows saw it at the smaller size. Stuck it in an adaptor and plugged it into my little ubuntu laptop and in disk utility it showed it as a full 8gb card with a smaller partition. Deleted the partition, stuck it back in my PC and windows formatted it to 7.49gb. If you have access to a linux machine, give that a try. Don't know why Windows ignored the gb or so free space, but linux didn't!