Prior to upgrading your EISA (Extended Industry Standard Architecture) partition to dynamic disk, Disk Management displayed it as partition one and you could Explore, Format and Delete Partition.
After the upgrade to dynamic disk, Disk Management shows it as partition 2, there is no drive letter, and the only command available is Help?
Disk Management is protecting the EISA partition from being damaged.
The only way to recreate the partition is to use the EISA utility provided by the OEM.
Prior to recreating the partition, back up any existing volumes on the dynamic disk and then use Windows Setup or the DISKPART command to delete the partition. You cannot use Disk Management to delete the partition or change the drive to basic disk until all the partitions have been deleted.