The HP EliteBook 8460p running Windows 7 64-bit is a retro-computing champion, but only if the graphics drivers are correct.
Bad driver signature or conflicting driver leftovers. Fix: hp elitebook 8460p graphics drivers windows 7 64-bit
This one is trickier. The official HP driver is old (Catalyst 13.1), but it is the most stable for docking stations and external displays on this specific laptop. The HP EliteBook 8460p running Windows 7 64-bit
Downloading the HP EliteBook 8460p Graphics Drivers for Windows 7 64-bit hp elitebook 8460p graphics drivers windows 7 64-bit
Open Catalyst Control Center → Power → Switchable Graphics → Set applications to "High Performance" (AMD) or "Power Saving" (Intel).