Answer first
Restart the scanner, confirm USB or Wi-Fi connection, open the scanner manufacturer app or Windows Scan, check permissions, and confirm the device appears in printer and scanner settings.
For USB, connect directly. For Wi-Fi, confirm the computer and scanner are on the same network.
Some printers print without the full scanner software. Open the correct scan app and test a simple preview scan.
Keep printer/scanner model, Windows version, app name, connection type, and exact error message.
Quick FAQ
Why can I print but not scan?
Printing and scanning may use different drivers, permissions, apps, and network discovery paths.