...(hopefully) without data loss:
WARNING: Only do this after you made perfectly sure that there are no dynamic-disc-only features in use by any partitions on the hard disc to process (such as RAID) and no logical partitions.
On the physical drive, in the very first sector at address 01C0:0 for the first primary partition (01D0:0/01E0:0/01F0:0 for primary partition 2/3/4), the ID byte for dynamic partitioning with value 42h can be changed back to 07h for basic partitioning.
To do that, a low-level disk hex editor such as dskprobe.exe from Microsoft Windows support tools can be used.
The Device Manager, included since Windows 2000, displays only devices currently connected to the computer, but stores hidden information about every device that has *ever* been installed. To be able to clean up such old device entries, device manager can be started with a special environment variable set:
C:\...> SET devmgr_show_nonpresent_devices=1
C:\...> START devmgmt.mscWhen started, in the ~~View~~ menu, the Show Hidden Devices option must be checked.