This solution is specifically for Windows, because I’m a conformist.
- Launch CMD as an administrator
- Start -> Type in CMD -> Right Click -> Run as Administrator
- Enter DISKPART into CMD and hit Enter
- Enter LIST DISK and hit Enter
- Find your memory card in the list and not whatever disk number was assigned to it
- Enter SELECT DISK # where # is the number of your disk and hit Enter
- Enter LIST PART and hit Enter
- These are all of the partitions, one of which Windows can see and one that it can’t.
- Enter DELETE PART # where # is one of the partitions you want to delete and hit enter
- Repeat for all the partitions you want gone
- Enter CREATE PART and hit enter
The memory card should now be ready for you to format however you choose (one easy way is through right clicking it in Explorer) and to use however you choose.