It sounds like you’re working with a specific, preserved build of Windows Vista Ultimate x64 SP2 (likely a curated “April Exclusive” edition from a collector’s scene). Given the OS’s age (RTM 2007, SP2 2009), any “useful feature” would need to be lightweight, compatible with Vista’s deprecated kernel (NT 6.0), and ideally fill a gap that modern apps no longer support.
Running this specific build today is an act of preservation. windows vista ultimate x64 sp2 final enu april exclusive