Just let's check you did the install without the scanner attached..? If that still doesn't work, then you can try installing the scanner drivers once again to your Win7 machine under XP compatibility mode.
Basically: Uninstall the scanner drivers you already put on on your Win7 laptop. Then put the scanner driver CD back in, look for the setup.exe or .msi install program on it; probably this will be in the root directory. Then right-click the icon, select properties. Under the 'Compatibility' tab, choose 'Windows XP' (or "Previous version of Windows).
Then off you go.