WD Black SN750 NVMe SSD hiding my old HDD

I installed a WD Black SN750 NVMe SSD in my Dell XPS 8930 and my Device Manager no longer sees my old HDD. I have checked with Dell and this SSD is supported by my motherboard. My BIOS can see both drives. Using Windows 10 and have updated all drivers and software. I was planning to switch my old drive into a data drive but cannot due to Windows not recognizing the old drive. Please help. Thank you.

The WD BLACK™ SN750 NVMe™ SSD delivers top-tier performance for gaming and hardware enthusiasts who are looking to build or upgrade their PC. Available in capacities up to 2TB, the WD Black SN750 NVMe SSD rivals some of the best performing drives on the market to help give gamers that competitive edge.

@jvo101 What is showing when you click on Settings>System>Storage? Be sure to look at links on the right side of the page too.