Windows achieves partition resizing when the free space and the partition are not adjacent - ie there is another partition in between - by converting the partition structure to dynamic disks and this has implications for how you use these partitions - eg you can't add another OS bootable partition to the disk - this may or may not be an issue. That is why it is better to stick to simple partitioning and use a 3rd party app unless you know what the consequences of your actions may be.