Try the following from a dos prompt

fdisk /status.

My guess is that the 10G drive will be listed with a 2 G dos partition and
the remaining 8G as unknown or not used.

If this is the case the drive was partitioned for a FAT file system which is
limited to 2G. Converting to FAT32 will not change the size of the
partition. It can be done but if using windows tools like fdisk it will
destroy all data on the existing partition.

Third part tools will allow changing the partition without destroying
existing data.
Partitionmagic from www.powerquest.com is a tool that is easy to use but
expensive. BootitNG from terabyte www.bootitng.com will also let you do this
but is a little more difficult to use. However, it has  30 day  free use
There are other applications around which will also do this. However, I have
not used any other and do not know much about them.