This works on Windows 8 64bit but follow the instructions I have written. The drivers are Epson, they are free, they are easy to install (if you follow my instructions) and they work on the Epson 1640SU.

When you get to the page that allows you to choose your driver, there is one for the 1200 series; either 1260 or 1270 I can't quite remember. Anyway, see below: Go to the following Epson site & download file 12180 (if the link doesn't open just highlight, copy and paste into your browser): Using Winzip or whatever, extract and install the file as per default settings.

Connect you Epson Scanner and go to Device Manager in Control Panel. The scanner will be shown but will have a marker against it.

Right click and select update driver. Select 'Browse my Computer' then 'Let me pick list of device drivers from my computer' (don't select or let the computer search for drivers because it will not find any). Choose 'Imaging Devices' and then click 'Have Disk'. Navigate to the folder that you have just unzipped and you will be offered a selection of Epson Scanners.

Download the latest version of Epson Perfection 1260 drivers according to your computer's operating system. Qsysopr Break Handling Programming there.

Choose the Epson 2400 and select install. Ignore all the warning etc that Microsoft throw up. The Device Manager will now show that you have an Epson 2400 scanner installed rather than the Epson 1640SU but that doesn't matter as your 1640SU will work perfectly well with the twain driver installed - including on 64bit systems like Windows 8. That's it and best of all; its free. I know this sounds excessive, but you can make an Ubuntu live usb, and boot into Ubuntu (even 64 bit) and your scanner will work fine. You can even save your images into your windows folders.

This works with two old scanners I have. Ubuntu has much better support for legacy devices.

Even old webcams and the like can be used in Ubuntu. Just a matter of rebooting.

If you really need to use your scanner this will work fine. For instructions on making a bootable Ubuntu live usb thumbdrive just google Ubuntu Live USB. Download Game Yakyuken Special Psx2. I know this sounds excessive, but you can make an Ubuntu live usb, and boot into Ubuntu (even 64 bit) and your scanner will work fine.

You can even save your images into your windows folders. This works with two old scanners I have. Ubuntu has much better support for legacy devices. Even old webcams and the like can be used in Ubuntu. Just a matter of rebooting. If you really need to use your scanner this will work fine. For instructions on making a bootable Ubuntu live usb thumbdrive just google Ubuntu Live USB.

Ironically, what I've been doing is almost this. I have Ubuntu on a second hard drive (only one screw and a few seconds to change on my Lenovo, a far cry from the awful Asus) and use that when I want to scan, among other things. But it's not a very elegant solution. This works on Windows 8 64bit but follow the instructions I have written.

The drivers are Epson, they are free, they are easy to install (if you follow my instructions) and they work on the Epson 1640SU. When you get to the page that allows you to choose your driver, there is one for the 1200 series; either 1260 or 1270 I can't quite remember. Anyway, see below: Go to the following Epson site & download file 12180 (if the link doesn't open just highlight, copy and paste into your browser): Using Winzip or whatever, extract and install the file as per default settings. Connect you Epson Scanner and go to Device Manager in Control Panel. The scanner will be shown but will have a marker against it.

Right click and select update driver. Select 'Browse my Computer' then 'Let me pick list of device drivers from my computer' (don't select or let the computer search for drivers because it will not find any).

Choose 'Imaging Devices' and then click 'Have Disk'. Navigate to the folder that you have just unzipped and you will be offered a selection of Epson Scanners. Choose the Epson 2400 and select install. Ignore all the warning etc that Microsoft throw up. The Device Manager will now show that you have an Epson 2400 scanner installed rather than the Epson 1640SU but that doesn't matter as your 1640SU will work perfectly well with the twain driver installed - including on 64bit systems like Windows 8.

That's it and best of all; its free. Steve It's works perfect on Win7/64 to. Only link to files doesn't work normal, but I download driver for Perfection 2400, change.exe to.zip, extract. Everything else is just like you explain.