As you are probably aware by now, Microsoft released Windows Vista Service Pack 1 to manufacturing on February 4, 2008. But even though the service pack RTM'd over a month ago, Vista users still don't have access to the gold bits of Vista SP1. Microsoft cited driver integration issues as the reason for postponing Vista SP1 RTM's availability another month and a half. Starting in mid-March, the service pack will be dropped via Microsoft Updates, Windows Updates and the Microsoft Download Center, with the localized versions planned for RTM in April, when the company will also start serving Vista SP1 through Automatic Updates.

But at the same time, Vista SP1 is indeed available for download. However, only the 15,000 testers involved in the Vista SP1 test driving process, along with Microsoft's Volume License Customers and MSDN and TechNet Plus subscribers got access to Vista SP1 almost immediately after Vista SP1 shipped.

An as far as the TechNet Plus and MSDN subscribers go, they can grab not only the Vista SP1 RTM standalone installer, but also the Vista SP1 RTM Slipstream (Integrated) ISO DVD for all the editions of Windows Vista, both 32-bit and 64-bit. Slipstream essentially means an ISO image of Vista plus SP1 already bundled together.

This week, Kathy Dixon from TechNet Plus subscriptions confirmed that "the full Vista install with SP1 integrated (also referred to as the Slipstream build) is now available for download." And the same is valid for MSDN, as a member of the MSDN Subscriptions program stated: "The first wave includes English, French, German, Japanese and Spanish versions of Windows Vista with Service Pack 1 are now available. These are available by clicking a Subscriber Downloads and Product Keys link from the Subscriptions Home page or the Subscriptions Management page - which takes you to the Subscriber downloads system."

The must-have information about the Vista SP1 RTM Slipstream (Integrated) ISO DVD files involves the hashes that are associated with the integrity of the downloads. The SHA1 hash codes for Windows Vista Service Pack 1 (Ultimate, Business, Home Premium and Home Basic editions) is bcd715a02739809e477c726ae4b5caa914156429.
The download is en_windows_vista_with_service_pack_1_x86_dvd_x14-29594.iso weighing in at 2,943MB. But there is also Windows Vista SP1 Enterprise available for download: f3032516ebcfafd03af886f8d5bc46e4b17ade23 and
en_windows_vista_enterprise_with_service_pack_1_x86_dvd_x14-55963.iso, just 2,140MB.