Convert dynamic disk to NTFS without data loss.
You only need a dynamic disk if you want more than 3 partitions

Actually 4
If you already have 4 partitions with NTFS, then an external disk will not be assigned a drive letter.
This has to be changed with disk management.
If you need fewer partitions, then a dynamic disk is not necessary.
Converting Dynamic to NTFS can be done with Diskpart, but that is not without risk.
Before you know it, you will lose everything.
The working method is as follows:
Clone the original harddisk.
Put that clone in a dockstation on a computer with the program AOMEI.
Follow the instructions.

If you succeeded and all the data is still there, you can clone that NTFS disk to that original dynamic disk.
It is recommended to use one more XP machine, especially when transferring files from a Win 7-8 or 10 disk, you will not have any problems with the assigned permissions that you will need to have first in order to access and copy the files.

XP has no problem with that at all.
Folders can be read and copied directly without the annoying rights management.

Click on the picture to enlarge