2TB is only the maximum with 32-bit file systems. We're well beyond that.
From Windows, you should be able to go into disk management, right click the partition and choose "Extend Volume".
We are digital librarians. Among us are represented the various reasons to keep data -- legal requirements, competitive requirements, uncertainty of permanence of cloud services, distaste for transmitting your data externally (e.g. government or corporate espionage), cultural and familial archivists, internet collapse preppers, and people who do it themselves so they're sure it's done right. Everyone has their reasons for curating the data they have decided to keep (either forever or For A Damn Long Time (tm) ). Along the way we have sought out like-minded individuals to exchange strategies, war stories, and cautionary tales of failures.
2TB is only the maximum with 32-bit file systems. We're well beyond that.
From Windows, you should be able to go into disk management, right click the partition and choose "Extend Volume".
Check what type of partition table you are using MBR vs GPT.
Thanks, I was able to fix this, and while the SSD shows up during BIOS for startup, only my other hard drives can boot up Windows. I can see the new SSD in BIOS (I set it to first priority) as well as Windows disk manager, and all the partitions / files / allocated size look fine.
EDIT: I am running UEFI. I actually cloned an MBR disk (my current C drive) to a GPT target disk (the NVMe M.2 SSD). Perhaps this is causing the issue, and if so, how do I get around it? Note that the M.2 SSD is 4 TB, so I assume I need the disk to be GPT rather than MBR.
Re-do your clone, clear the suggested layout in the bottom (target) box and drag down the partitions from the source drive - you should be able to drag the right edge of tha last partition in the target bi's to use all the free space.
I'm not in front of my machine at the minute but I've done this loads of times and that's about the gist of it 👍
This has nothing to do with datahoarding. You probably had windows installed in legacy mode (mbr). There are ways to switch it to uefi(gpt) but with your limited knowledge its easier to backup and reinstall