The lockdown capability is part of the broader set of User Account Control (UAC) features aimed at limiting the administrator-level access that Windows users typically have had on their PCs.

Support for functions like UAC will finally give Windows some of the security functions that have been available in rival operating systems such as Unix for years, said Andrew Jacquith, an analyst at Yankee Group Research Inc. in Boston. But Microsoft needs to ensure that the functionality doesn't come at the cost of usability and compatibility with previous applications, he noted.