If you want to actually use the OS, see the Aero glass effects, and run old software, you shouldn't look for a "simulator" but rather a Virtual Machine image What you need: Hypervisor: Oracle VM VirtualBox VMware Workstation Player (both are free for personal use).
Feature concept (single-sentence elevator): A downloadable, browser-optional Windows Vista Simulator that recreates the look, sounds, quirks and workflows of Vista with interactive mini-challenges, guided nostalgia tours, and modern conveniences (snapshots, sandboxed apps, shareable clips) so users can both reminisce and learn why Vista felt so unique. windows vista simulator download
Windows Vista Ultimate (64-bit) : Microsoft Corporation : Free Download, Borrow, and Streaming : Internet Archive. Internet Archive If you want to actually use the OS,
These are lightweight programs or sites designed to mimic the look and feel of Windows Vista without actually installing an operating system. Windows Vista Simulator (Xsolla) Internet Archive These are lightweight programs or sites