SEATTLE - Microsoft Corp. launched a Web site yesterday for managing personal-health and medical information, jumping into an industry whose digital future is clouded by privacy worries.

From the consumer's point of view, Microsoft's HealthVault site is part library, part filing cabinet, and part fax machine for an individual or family's medical records and notes.

The free site is tied to a health-information search engine the software company launched last month. It gives users a repository for data such as medical histories, immunizations, and records from visits to doctors' offices and hospitals, as well as measurements from devices such as heart-rate monitors.

Users can dole out access - in the form of e-mailed invitations - to different slices of their private health data to doctors, family members and other people they trust as the need arises.

The HealthVault site itself does not do much more than provide a window into stored information and a mechanism for sharing it. Microsoft hopes hospitals, doctors' offices, advocacy groups and insurance companies will build Web applications that patients will want to use.

Microsoft said it planned to support HealthVault with advertising revenue from the search portion of the site.

In an interview, Sean Nolan, chief architect of the company's two-year-old Health Solutions group, characterized this "beta" launch of HealthVault as an early step into a difficult industry.

For one thing, 80 percent to 85 percent of doctors in private practice do not keep electronic records, and hospitals are not much better, according to Lynne Dunbrack, program director of the market-research group Health Industry Insights. Where electronic records do exist, there is no guarantee that any two providers will call the same treatment or lab work by the same name.

And some of the best sources of comprehensive health-records data - major insurance providers, many of which already offer personal health-records tools - have not agreed to build applications that work with HealthVault.

Even if Microsoft were able to get providers and insurance companies to feed data into HealthVault, it is not clear consumers would want to access it over the Web.

Dunbrack said consumers did not seem to know that insurers and some employers already offered some form of personal-health records.

And while consumers have been willing to send financial details over the Web despite identity-theft horror stories, they remain concerned about privacy.

Microsoft's Nolan said gaining consumers' trust was a potential problem, one the company tried to address by spelling out what data would be shared each time the user connected to a new application or gave someone new permission to see a record.