Partition label is an optional attribute, and easier to identify. For example: SYSTEM Partition, TOOLS, Vmware Backup, Games and etc. Maybe sometimes Windows will not follow the order of letters to set label, you can change drive label with command promprt here, and followings are very detailed information to change drive label with third-party system utility:
Launch the Macrorit Partition Expert, you'll see all detail information of the partition and disk.
Right-click the volume whose Change Label you want to change, and then click Change Label.
Enter a new label in the Partition label window.
Click OK to add the pending drive letter changing operation.
In the end, Click "Commit" button, the changes can take effect.