I use a second internal drive, E: to backup my primary data drive, D using a product called Beyond Compare. It is not automatic but very versatile. 2TB SSD C:, 18 TB D:, and 18 TB E: is my drive info.

I use a second internal 18 TB internal drive. I use a product called Beyond Compare to replicate CR2 and CR3 files from the primary data drive D: to the secondary drive E:. I exclude folders which contain copies of RAW files and exclude JPG files from the compare and copy process. My C drive is an SSD, 2 TB. When the the data drives are full I replace them both. Over the years the drive sizes have increased.

I purchased a new HP Omen desktop with Windows 11 sometime in March. My Windows 10 was kept as a backup. I had numerous crashes, as many as three in one hour. I completely teinstalled Windows 11. There was no change. HP took my computer for a few weeks and replaced the graphics card but it made no difference. Eventually, after several months and maintaining the latest updates for all software and the OS, it stopped crashing. It works well now. I don't know if it was an Adobe, Nvidia, Microsoft, or some other upgrade that fixed it. My advice is be certain to use latest available software. I use Lightroom and Photoshop, primarily. I think you will be good with the upgrade. Good luck!

You should not delete ANY files until you have a much better understanding of the situation. Lightroom has a , "Show in Explorer" function which indicates where the particular picture, presumably a RAW file, being viewed is stored on the hard drive. The XMP file is useless without the RAW file of the same filename. I am 79 and understand your confusion.
My Canon RAW files have a file extension of CR2 or CR3. Your manufacturers RAW files may differ. Lightroom does not store your entire picture. It stores a small image and editing information. What Lightroom contains is useless without the RAW file.

It is a known bug in LR12. Adobe support said it should be fixed next week. I have seen workarounds on YouTube but they did not work for me. Reverting LR11.5 results in losing edits made in LR12 so be careful.

It is a known bug with LR12. Expected to be fixed next week.

I have used Lightroom since my eos30d days. I have endeavored to save all RAW files. Having learned to better use Lightroom, and a little Photoshop along the way, I can now easily make some previously unacceptable photos acceptable. I am happy that I saved the RAW files. It does require much hard drive space which is not a problem for me, but I can see where it may be for others. If profit is the only motive, then my way would not be acceptable.

Canon said they "... replace the rear element. That's what was causing bad focus." It has never been dropped so I don't understand why it failed. However I am somewhat relieved that they found something wrong. Thanks everyone who commented on my problem. I took some ballet and some college softball photos with prime lenses over the weekend. Those photos were tack sharp. It was a pleasure to use them and to zoom with my feet for a change. I do love the bokeh. I was tending to be a bit lazy with the 24-70. I should receive it tomorrow and will see if I notice a difference in its performance. Some 24-70 pictures were fairly sharp which was troubling because I didn't want to send off for repair a good lens. Thanks again for the replies.

Thanks Gene51. I will be more conscious of exposure in the future.

I don't expect them to find anything wrong but at least I will have renewed confidence. I will use the camera tonight for a ballet performance with an 85 mm L series lens. I am keeping my fingers crossed. This is my only silent camera. I has worked well since those blurry pictures were taken.

Thanks AzPicLady. I sent the lens to Canon. I should know Friday what if anything they find.

Thanks jeep_daddy. Not a paying customer but that will not affect my efforts. I will try to do a reshoot. I read with interest the information you included. I read a portion of the manual pertaining to Electronic Shutter. A reason I purchased this camera was to be able to shoot Ballet performances in silence. I am returning the lens to Canon for repairs with my fingers crossed and hoping they find something wrong.

AzPicLady thanks. I am sending the lens but who knows if that's the problem?

Thanks Gene51.