Go here
You can then extract the driver to a folder such as C:\lpb810 and go forth to point Windows to the folder when asked for a location of the driver. This is a Windows 7 driver but it will work just fine with Windows 8.1
I have a Canon 4200F scanner that windows 8.1 will not support natively but using a Windows 7 driver and software I made it work just fine using the Existing Canonscan toolbox. You however cannot support it under native windows 8.1 driver but it will still function just fine.
If there is a choice of 32 or 64 bit then if your computer is dual core go with the 64 bit otherwise stick to the 32 bit drivers.
Good luck!
P.S. Sadly Linux does not support the Canon 4200F scanner so that nukes it for any Linux Distro. If you have a solution for that I welcome it.