What is FAT32?
FAT32 is a commonly used file system in Windows. This term refers to the way that
Windows use to store data on the hard drive. FAT stands for "File Allocation
Table", which keeps track of all your files and locates them on the disk. Even
if a file becomes fragmented, the file allocation table can still keep track of it.
FAT32 is an improvement of the original FAT system, because it uses more bits to
identify each cluster. This enhances the management and efficiency of a
computer.
Why need to shrink volume?
Most users face the problem of imbalanced allocation of volumes or said partitions.
It may cause many troubles like low disk space, running out of space and so on.
Especially the lack of system space can make a computer work very slowly even lead
to data loss. In such situations, one ideal way is to shrink one volume to increase
another. Sometimes, maybe users just want to create a volume. It can also be
realized by shrinking volume.
How to shrink FAT32 volume with AOMEI freeware?
As you know, there’s built-in Disk Management in Windows system. However, it can not
do either extending or shrinking FAT32 volume.

Here, volume E is FAT32 file system. If you right click on it, both "Extend
Volume" and "Shrink Volume" options are greyed out. Due to its own
flaws, Disk Management can only resize NTFS volume rather than FAT32 as well as
FAT/FAT16. Thus, a third-party partition software is needed. Following instructions
will show you how to shrink FAT32 volume with free software - AOMEI Partition
Assistant.
First, you need to download Partition Assistant
Standard Edition (free). Install and launch it.
1. Right click the FAT32 volume you want to shrink. Select "Resize Partition".

2. You can adjust its size by dragging the border (either left side or right side).
Then click "OK".

3. Now there’s a new unallocated space. Click "Apply" to save the
change.

Tips: Before clicking "Apply", you’re able to perform
other operations, too. Such as Create
Partition, Split Partition, Merge Partition, etc. Generally, AOMEI
Partition Assistant breaks many limitations of built-in Disk Management. You’ll find
more functions that help you to optimize your computer.