Windows 10 Boot Camp Partition Disappeared

[JHahn7837]

I have been running Windows 10 via Boot Camp for several years. I finally decided to upgrade the OS X side from El Capitan to Catalina. I had no issues after the update except the default boot disk reverted back to OSX. I was able to boot into Windows by holding alt/option. A few days later, I was having a wifi issue in Windows and so I booted into the OSX side to download the latest Windows Support Software. During the software download I received an error stating that the Windows Support Software could not be saved to the specified location (I had forgot to insert a valid USB drive). I had to hard shut down the computer. Since then, my Windows partition is no longer visible in Finder or Disk Utility, nor is it showing up as a boot disk in system preferences. It appears that section of the Hard Drive is showing up as free space. I am looking for some direction on how to troubleshoot and begin to restore my Boot Camp partition. Any help is appreciated.

 

[chscag]

The hard shut down may have caused corruption to the Windows 10 boot sector. I've seen that occur with earlier versions of Windows. Do you have a backup of your Windows 10 installation? Before you try to correct anything, do a NVRAM reset to see if the Windows boot sector will come back to life. If that doesn't work you may be looking at a reinstall of Windows 10 and a restore from your backup.

 

[JHahn7837]

I have been using windows backup weekly since I've been running dual boot as the windows side has almost everything I would care about. I have the original windows 10 bootable USB and my portable backup drive. Haven't tried a PR reset yet. Trying now...
[automerge]1584501241[/automerge]
No change. The boot camp partition remains a ghost on the whole system.

 

[chscag]

Yeah, sometimes it works, sometimes not. Well, at least you have a good backup but it's still a pain to have to reinstall.