How to Partition a Micro SD
Micro SD cards used to hold only a few megabytes of storage space, and as such there was almost no reason to try and partition them into more than a single drive. Today, however, the storage capacity of these little plastic squares is quickly climbing into the gigabytes and beyond. Because of this, many users wish to partition their Micro SD cards into smaller drives in their own right. This can be accomplished using the Windows partition manager.
Insert your micro SD card into your computer's card reader.
Right-click your My Computer icon and select the "Manage" option.
Click the "Disk Management" option in the left window pane. This will bring up a list of all the drives--including your SD card--that are available on your Windows machine.
Right-click the Micro SD card in your Disk Manager window and select "Shrink Volume." A window will pop up showing you the full size of the Micro SD card.
Enter the desired size of your new partition and click the "Shrink" button. This will create a volume of unused space on your Micro SD card equal to the number you typed.
Right-click the unused space you created and select "Create New Simple Volume."
Follow the on-screen instructions, then enter the size of the partition you wish to create.
Select a drive letter for your new partition--or leave it as the default selection--then select the "NTFS" file system in the "Format" window and type in a name for your new partition. Click "Next" to start the formatting process. When the process is finished, your new Micro SD partition will be ready for use.