HP L7680 Scanner & Software function - cD does not load fully
This is an educated guess but your problem is most likely a driver/software file conflict which is causing the software to bork before it completes the installation.
In all honesty the HP software is bloatware that is frequently identified as more trouble than it's worth. So, my recommendation would be to try and locate a more suitable software package that will work with the scanner to do what you want instead.
You are probably best to download the basic driver only package for your unit and then completely remove the old software before installing fresh (remember to unplug the printer before you install the new drivers).
I appreciate that this is not the most elegant solution but as I noted the HP software is not overly user friendly and in the interests of retaining your hair, sanity and keeping therapy bills to a minimum I'd invest your time in finding a more suitable application that will work with a TWAIN scanner (which the HP L7680 should be).
Hope that helps and good luck...