SanDisk 8GB microSDHC format error : reads now as 3.6GB card

I am having a similar problem with the same type of memory card. Except when I insert my card into my phone it doesn’t read the card. It shows no device available. So I downloaded the disk storage format tool you advised him and it would not format the card. Am I missing the drivers for the card? If so, where can I go to get them?