Microsoft on Wednesday released details about its first service pack (SP1) for the Windows Vista operating system, an update that features security upgrades, improved performance, and support for emerging hardware and standards.

Microsoft released Vista to the general public in January and SP1 marks the first major upgrade to the operating system since its debut.

SP1 will be released to a "moderate sized audience" in the next few weeks and will be available to the general public by the first quarter of 2008. An exact date for release will be set after Microsoft evaluates customer feedback from SP1 beta.

"A later pre-release of SP1 will be available to a larger group of testers via MSDN and TechNet subscribers," White said.

Vista SP1 will be available in three forms: express, stand-alone, and slipstream. The express version allows users to download a pared down version of SP1 online. It will take up approximately 50MB for x86-based operating systems and will only send the changes needed for a specific computer.

The stand-alone option is recommended for computers with limited Internet connectivity, according to Microsoft. It packs a larger download size than express, but users can apply a single package to any Vista version and language combination within a given platform. Users must have administrative access to install stand-alone.

Microsoft recommends that systems installing express or stand-alone have a minimum of 7GB of free disk space for x86 based operating systems and 12GB of space for x64-based systems.

The slipstream version of Vista SP1, meanwhile, is Vista that already includes the service pack. Companies can use it to deploy Vista on new computers or to upgrade existing ones. Slipstream availability will be limited, but volume licensing customers will have access.

Continue for more details on Vista SP1's upgrades and enhancements...