When Vista launched, the computing world was in transition. While Windows XP had a 64-bit version, it was rarely used due to driver incompatibility. Windows Vista was the first operating system to ship 64-bit versions to the mainstream consumer market simultaneously with the 32-bit versions.
: While the full OS isn't hosted there, you can still find the Windows Vista Service Pack 1 Standalone DVD ISO , which contains both 32-bit and 64-bit updates. windows vista iso 64 bit