I bought a bigger microSD card for my Samsung Galaxy S7 Edge. I took out the old card and copied its content to a folder on my PC, via a card reader. Then I put the new card in the reader, formatted it and started copying the data back onto it. One rather irrelevant .jpg file was signalled as damaged, so I skipped it, then some folder required admin rights to be copied, so I clicked the "continue as root" button. So far so good. But finally a folder named "cache" couldn't be copied or skipped, and the only option I was left with was to abandon the whole copying process. I searched my backup folder for "cache" subfolders and there are quite a few of them, but all are buried deep in the recesses of the directory tree, so none of them is THE Android cache that I hear a lot about when googling for a clue. Any ideas what it is I'm up against, and how to solve it? My PC is running Windows 10. TIA!
If your Windows ask you for admin permissions something is wrong - this should never happen as you just copied it from the other SD card.
Anyway copying and SD card file by files is IMHO not a good idea because the Windows Explorer does usually hide certain files.
Therefore I recommend to use a backup tool or alternatively use a compression program like 7Zip/WinZip/WinRAR and zip the whole source SD card to one file on your hard disk.
Then switch to the new SD-Card and restore the backup respectively decompress the created archive to the new SD card.
Edit: Note that a lot of SD cards on the market are "fake SD cards": Their controller has been manipulated to make the SD card look larger than it is (e.g. the card has 16GB flash memory but tells the Smartphone/PC it has 128GB). Writing to such a card will earlier or later end in a total disaster. Therefore I strongly recommend you to test any new SD card before using it. One of the best tools I know for doing so is a small Windows tool named h2testw (Language German and English). It writes files with a special pattern to the SD card until it is full and then reads it and tests if the pattern of every file is correct.