I'll try to better isolate the problem over the next week, but clearly Windows is writing to the drive. I'll see if I have the same issues with deleting those temp files and if there's a way around it. http://www.cpaptalk.com/viewtopic/t110838/Windows-10-and-SD-Cards.html#p1063160 Thanks for the li...

Registered just to add a "me too". It started happening a while after installing Win10, so not sure if it's due to an update. I've used the same card, card reader, and same PC in the past without issues. It's happened twice before today (but I don't regularly download data - only when curious), so I...