Microsoft has started development of the first service pack for Windows Vista, even though the operating system will not start shipping to consumers until next week, and has been available to large enterprises for only two months. 

The software vendor has been contacting businesses that want to volunteer as beta testers.

Service packs typically contain bug fixes and minor feature enhancements, but rarely make any major changes to the software.

The Service Pack 2 release for Windows XP was an exception in that it delivered a major overhaul of the operating system's security, including the addition of a firewall.

Microsoft has not yet disclosed a planned release date or a schedule of issues that it plans to tackle with the update.

Service Pack 1 for Windows XP was released 11 months after the launch of the operating system. But in the case of Windows XP, the software was plagued by a slew of bugs and compatibility issues that required an early repair.