The ScanSnap S1500 is a legend that refuses to retire - and a special case: it has no standard TWAIN driver, so it works only through its own ScanSnap Manager software. The scanner is long discontinued, the brand has moved from Fujitsu/PFU to Ricoh, and the setup disc is useless on modern Windows - but the software still exists, and the S1500 still scans happily once it is installed the right way.
Quick answer
Download ScanSnap Manager for the S1500 from the official ScanSnap support site (the PFU/Ricoh scanner support pages - search "ScanSnap S1500 downloads"). Install it BEFORE connecting the scanner, then plug in USB and power the scanner on by opening the lid. Windows setup alone will not do it - the S1500 works only through ScanSnap Manager.
The S1500 speaks only to ScanSnap Manager - without it, Windows and third-party scan apps have nothing to talk to. This is normal, not a fault.
The bundled software predates Windows 10 - only the last ScanSnap Manager builds from the official support site install on current systems.
Connecting the scanner before ScanSnap Manager is installed leaves a dead device entry that confuses the real setup.
The S1500 wakes when the lid opens and sleeps aggressively; a worn USB cable or a hub makes it flicker in and out of existence.
If you do not know the exact model, several devices need attention at once, or the manual route did not find a match - Outbyte Driver Updater identifies your installed hardware automatically and updates the drivers from official sources, with a backup before every change. The scan and diagnosis are free.
Download Driver Updater Downloads Outbyte Driver Updater for Windows 11, 10, 8 and 7. Free 2-day trial, no credit card required.Officially the S1500's support list ends at Windows 10 - the model is discontinued. In practice the last ScanSnap Manager build installs and scans on Windows 11 for many users, with no guarantees from the vendor. Install it in the driver-first order and test; on a machine where it refuses, Windows 10 remains the safe harbor.
Mostly no - there is no TWAIN driver, so apps that expect one cannot see it. ScanSnap Manager does the scanning and hands files (PDF, JPEG) to other programs; automation goes through its profiles rather than through the apps directly.
No - ScanSnap Home does not support the S1500. This model stays with ScanSnap Manager; that is the package to download from the official support pages.