Windows OS not showing up in msconfig boot options

I have a refurbished Dell Precision 7510, running Windows 10 Pro (Build 19042.867). Two days ago, Windows Update started failing at updating my OS and displayed the typical message "We couldn't update windows, undoing changes" at start. I checked Windows Update options and I got a 0x800706be error. A quick google search showed that some registry files may have been corrupted in the previous update, so I decided to try and run windows in safe mode to uninstall the previous update and try to update form a older version of windows. To my surprise, my OS is not being displayed in the boot tab of msconfig. Here's a screenshot of my msconfig window.