This is Vistascan v3.51s (for scsi scanners like the 610S) for Windows 9x. It also includes the driver for the original Acard scsi controller card.
Unzip this download file to a temp folder. You will have 4 files:
vsc351sa.exe, 6,740 kb
vsc351sb.exe, 4,825 kb
vsc351sc.exe, 9,054 kb
vsc351sd.exe, 2,418 kb
Launch the first file (vsc351sa.exe) by double-clicking it to start the installation.
Follow on-screen prompts. Be sure to not select Acard scsi controller when installing unless you have the original Acard controller. The installation will have provisions for telling it you have a different scsi controller card.