Partition Magic, the product of Symantec, is the most important partition resize software under Windows 98, Windows 2000, and Windows XP. Since being acquired by Symantec, Norton Partition Magic has not been upgraded. Maybe you can still use it under Windows 10. However, it is so unstable that you have a great chance to meet problems or system crash when resizing Windows 10 partition.
So I strongly recommend you not to use it to resize Windows 10 partitions. I will show you how to resize Windows 8 partitions with a partition magic alternative - Qiling Partition Master Free Edition (Freeware) in this article.
As a partition magic alternative tool - Qiling Partition Master Free Edition, offers a simple and convenient way to manage your partitions, runs well on Windows 10. Say, it enables you to extend the system partition, Create, Delete, Resize/Move, Copy, Merge, Split partition under Windows 10.
Step 1. Shrink partition to free up space to extend partition.
If the hard drive has enough unallocated space to extend the target partition, jump to Step 2, and continue. If not, free up space first:
Step 2. Extend target partition.
Click on the target partition and select "Resize/Move".
Drag the target partition handle into the unallocated space to extend partition.
Step 3. Keep all changes.
Click the "Proceed" to keep all changes.
For more detailed information, please visit resizing and moving partitions.
Besides, partition manager features, Qiling Partition software also provides some other features like Partition Recovery Wizard to recover deleted or lost partitions, Copy disk & partition wizard to upgrade or backup disk.