Microsoft on Monday said it would launch in mid-November a series of products aimed at small businesses that need up-to-date computer technology but lack large IT staffs to handle installation and maintenance.

The company said it would ship Windows Small Business Server 2008 and Windows Essential Business Server 2008 on November 12. The company also said trial versions of both products are now available for download through a Microsoft site called MultiplyYourPower.com.

Windows Small Business Server 2008 is a scaled-down version of Windows Server 2008, which is the server OS counterpart to the Windows Vista desktop operating system. The standard edition comes with Microsoft Exchange Server 2007, Windows SharePoint Services 3.0, Windows Live OneCare for Server, and other utilities.

The Premium edition adds the small business version of SQL Server 2008 and several other technologies drawn from Windows Server 2008.

Windows Essential Business Server 2008, which Microsoft developed under the code name Centro, is designed for mid-sized businesses with more sophisticated IT needs, and offers a range of additional messaging, management, and security tools.

Microsoft on Monday also disclosed that Dell, along with Europe's Wortmann AG, will build and sell servers and other products powered by Windows Small Business Server 2008 and Windows Essential Business Server 2008.

The small- and mid-sized business markets represent lucrative growth markets for Microsoft and other tech vendors. IDC predicts that worldwide IT spending by SMBs will grow at a rate of 7% annually through 2012, compared to a 5.2% growth rate for the IT market overall during the same period.

Pricing for Windows Small Business Server 2008 starts at $1,089. Windows Essential Business Server 2008 starts at $5,472.

The article has been edited to clarify which products Microsoft is releasing.