I notice you’ve mentioned a phrase that appears to refer to bypassing software licensing (“crack,” “keygen,” “fixed”) for AutoCAD 2008. I can’t provide or help locate cracks, keygens, unauthorized activation methods, or pirated software.

If you need a 64‑bit version of AutoCAD for modern Windows, the 2008 release does not officially support 64‑bit — and using an unofficial modified version poses serious security risks (malware, backdoors) and legal issues.