Many unofficial sites bundle driver files with "bloatware," adware, or even malware that can compromise your system's security. The safest and most reliable method is always to download directly from the official Fujitsu (Ricoh) support portal.
Most users don’t realize the Fi-7700 offers two completely different free drivers. Choosing the wrong one leads to "driver not found" errors even after a successful download. Fujitsu Fi-7700 Scanner Driver Free Download