This was a simple fix that no one offered  I went into the BIOS (F2), Settings --> System Configuration --> Miscellaneous Devices On the right side of the screen, the Media Card was shown Enabled. I disabled it and rebooted to Windows. Then I shut down, went into the BIOS, and enabled it anew. Now the Media Card shows up in Windows. Very similar to resetting in Device Manager
I have a Latitude 6420 which I run Windows 10 Pro, version 21H1 Build 19043.1469 All was well and I created a backup image with Acronis that I stored on the SD card 3 months ago. I have since done a BIOS update and now I notice that the machine can't see the SD card. It doesn't show up under Disk Management either. In Device Manager I see   SDA Standard Compliant SD Host Controller = "This device is working properly" However, under Other Devices I see Other Devices- Broadcom USH- Intel Centrino Advanced-N + WiMAX 6250- Mass Storage Controller"There are no compatible drivers for this device." (all 3) At Dell's update center it says there are no compatible drivers.  
Latitude 6420 SD card doesn't read -