USB HDD problems

I have just received a Seagate Backup Plus, 4Tb, USB3 drive. I am still using Windows 7 Enterprise which I like and am usually competent in using. The backup drive came with software but I was not interested in using that. I went into Computer Manager, shrank the main simple volume by half and formatted it then went to create the new, unallocated space into a second drive, each partition then being 1.9Tb. Unfortunately, the second partition will not allow itself to be created as a volume of any sort and the drive now reads as a 2Tb. I went back into disk manager to extend the partition into the unallocated space but it has completely disappeared. As it is not an internal drive, can I go into the bios and delete the partitions even though it is an USB drive. :confused

 

No, Disk Management only works from within Windows. Are you running 32-bit or 64-bit Windows (2 TB limit for 32-bit).

Personally, I don't use Windows Disk Management for partitioning my hard drives. I use AOMEI Partition Assistant from which I created WinPE bootable media so I can work on my hard drives pre-OS (I run two internal drives with XP Pro on one and Vista Ultimate on the other and two USB drives with Win 8.1 on one and the other is strictly a data drive).