Old driver files as a clean install will result in a warning window like bellow.
This warning is not fatal to the install, but many customers reported us this wishes. The WHQL process assigns a new digital signature to the CAT files, and prevents the warning window from appearing. With the release of Windows XP, Vista, 7 64-bit edition, Microsoft requires signed device drivers. It is likely that this requirement will carry forward to new operating system releases as well.