Do you have Win7 32-bit or 64-bit? If you have the 32-bit, the driver you need is here: http://www.usa.canon.com/cusa/support/consumer/scanners/canoscan_series/canoscan_lide_80#DriversAndSoftware
. This driver works for Win2K-Win7. This is an unsigned driver and probably will not work in Win7 64-bit.
In my experience, Canon is very poor at supporting their scanners for 64-bit OS versions. In fact, they do not have a Vista 64-bit compatible version of the drivers for this scanner.
The only solutions I have found are tedious. 1) Keep your old computer that works with the scanner and transfer files on a USB drive or optical disc (RW is better for this). 2) Set up a virtual computer with an OS that works with the scanner. If you have Win7 Pro or Ultimate, you can do this for free. Download Microsoft's Virtual PC and the XP mode package. Install both in order. For other versions of Win7, you will need a virtualization program (Parallels, Virtual PC, VMWare) and a licensed version of XP (or other OS that will work with the scanner). Set up the virtual computer program and install the OS.
Next install your scanner to the virtual computer and use it in that "machine". You may need to transfer files to external or optical media to share the documents. You can't install a printer on both the virtual computer and the real computer at the same time (at least with XP mode).
I hope this helps.
(I tried using the compatibility mode and accepting the unsigned driver for a Win7 Home Premium 64-bit machine for a different Canon scanner. It didn't work and I have dealt with a number of old hardware and new OS issues over time.)