I downloaded Windows 10 on July 28. I have had nothing but problems . Between 2 and 12 duplicates of many photos. Any duplicate deleted will delete all copies and leave a non removable and non available photo entry. Also renaming or renumbering a photo will make it no longer available. Does not effect photos after August. I had about 70,000 photos with windows XP. When I went to Windows 7 pro, it reloaded to 107,000. At least I could delete the duplicates with no problem. When Windows 10 installed, I ended up with 307,000 photos. Today I have over 310,000 photos. Totally unmanageable. I do not recommend Windows 10 until they address this problem. I contacted customer service 8/12/2015 and was told it caused by a virus and after the virus was removed it would be resolved. Not happening! Be very careful. I have lost a lot of photos already. Any change to Collections, Pictures, or Photo Gallery is also done to the others. I will try to resolve this again but will probably return to Windows 7 pro next week.
I assume these "duplicates" are seen in the photo gallery, but the actual photo on your disk is not duplicate. I very much doubt that that the Win 10 upgrade touches you personal files, such as photos.
Upgraded ??? to Windows 10 Destroyed about 20% of my Photos. Can not load new material from my SDHC Card .I have to go back to 7 I guess! Had no problems with Zoom Browser with 7 - Windows10 initially accepted downloads from ZB - Not anymore!