There is a power struggle between the generic drivers that Windows installs for Samsung and those of KIES.
Possibly in one of the updates, Windows has wiped out KIES.
The ideal thing now is to uninstall KIES, restart, run a registry cleaner (ccleaner, Gladys you use, etc). Now you reinstall Kies and restart, then disconnect the PC from the internet, start KIES and, with the phone active, connect it with its original cable to a rear USB connection of the computer.
Check that the PC has detected it with the characteristic USB connection sound (the ding-dong). Wait a few moments and let it finish recognizing it.
If everything has gone well, it will have already detected it, in case not, use the connection tools of KIES. When it has connected correctly, you can already reconnect to the internet.
Goodbye