Can't access "Unallocated" partition to map, format, or anything else

[Netster]

I have a new 3Tb drive in a Win 10 PC.
After initializing, the drive automatically separated into 2Tb and 1Tb partitions, the latter named "unallocated."
I can't access, read or format the 1Tb, and can't expand the 2Tb one.
Is there any option to at least format and map the smaller area to use it?
Thanks,
Jon

[aoz987]

how are you seeing the partitions? with PHDM 16? upload a screen image

[fireworker]

https://www.techrrival.com/mbr-vs-gpt/