I am using scanbutton driver for my old benq scanner but after some time it stop working, and all my effort to get the driver or any driver to work with it is abortive,please kindly help me out.

i just helped a friend out with the direct link for downloading his own benq scanner 400u driver too, i cant open the site now so follow these steps,
go to benq.com click on products, then choose the second option (Not Computers and not comunication), then choose scanner,, then choose model, then choose driver, then choose ur OS version , e.g XP, let me know how it goes