This is from the installation disk I've got together with my scanner. Installation 1) Plug in the scanner, 2) Power on the scanner, 3) If the system is not prompting you with a Plug and Play Dialog for unknown device go to 'Add New Hardware' (Control Panel) and install the minidriver (PV8630.INF/SYS) manually. 4) Then install the TWAIN driver for the scanner by starting SETUP.EXE.
Worked in my case (Windows 98) so far. I hope this solves everyone's problem with this scanner.