There should also be a file called KN7000mn.bak on your SD Card, which contains a copy of the KN7000mn.INF data.
I seem to remember that a long time ago, when the .inf file got corrupted on one of my SD cards, I just used Windows Explorer to delete the .inf file and renamed the .bak file to .inf - That fixed the problem.
However, before I did the operation, I used Windows Explorer to copy the 'PRIVATE' folder on the SD Card, to a folder on my PC hard drive, as a back-up - just in case

Might be worth a try............