Microsoft has started to distribute Windows Vista SP1 automatically to the users who have the Automatic Update feature turned on.

On March 18th, Windows Vista SP1 was made available for customers who chose to manually download and install it from the Microsoft Download Center or Windows Update in English, French, German, Spanish, and Japanese. 

Still, not all the Microsoft clients that have the Automatic Update turned on will receive Windows Vista SP1 update.

“While we're beginning automatic distribution today, you might not see it right away since the distribution process is very gradual.  As I called out on April 7th, we'll be distributing the service pack slowly so that we can help Windows users have a good experience,” wrote Chris Flores on Windows Vista Blog.

According to Microsoft, Windows Vista SP1 will not add new features, but instead it will address key feedback received from its customers.

As Microsoft explained, the updates packed in Windows Vista SP 1 fall into three categories: Quality improvements, improvements to the administration experience and support for emerging hardware and standards.

Amongst other things Vista SP1 will enhance BitLocker Drive Encryption (BDE) by offering an additional multifactor authentication method that combines a key protected by the Trusted Platform Module (TPM) with a Startup key stored on a USB storage device and a user-generated personal identification number (PIN).

In addition, the update will add support for upcoming standards and hardware, such as Direct3D 10.1, Secure Sockets Tunneling Protocol (SSTP), Extensible Firmware Interface (EFI), and the Extended File Allocation Table (exFAT), a file system for Flash drives.

The service pack will include support for Secure Digital (SD) Advanced Direct Memory Access (DMA), which will be on compliant SD host controllers soon, to improve transfer performance and decrease CPU utilization.

Many of the changes in Windows Vista SP1 will address also the administration Experience. Administratos will surely appreciate the improvements to Group Policy management.

In the SP1 timeframe, administrators can download an out-of-band release that will give them the ability to add comments to Group Policy Objects (GPOs) or individual settings and search for specific settings.

The new update will help the users to install their legal copy of Windows Vista without having the same problems as before. In case they have an illegal copy of Windows Vista users will get pop up messages, which notify them about the status of the software along with information about how to make the software legal.

Microsoft launched the consumer version of its Windows Vista operating system on January 30 last year and it’s considered the most expensive software programme in the world which took five years and 7 billion dollars to develop. In January, Microsoft announced it has sold 100 million copies of Windows Vista so far.

Earlier this week, Microsoft also announced it will release the Windows XP SP3 on April 29. Windows XP Service Pack 3 (SP3) includes previously released Windows XP updates, including security updates and hotfixes. It also includes select out-of-band releases, and a small number of new enhancements, which do not significantly change customers’ experience with the operating system.

Microsoft is not adding significant Windows Vista functionality to Windows XP through SP3. However, SP3 does include Network Access Protection (NAP) to help organizations to work with the new features of the Windows Server 2008 operating system.

NAP is a policy enforcement platform built into Windows Vista, Windows Server 2008, and with which a user can better protect network assets by enforcing compliance with system health requirements. Using NAP, the users can create customized health policies to validate computer health before allowing access or communication and automatically update compliant computers to ensure ongoing compliance.

Besides NAP, Windows XP Service Pack 3 will include Management Console 3.0, which appears in Windows Server 2008 and Vista and the new Windows Installer 3.1.