Microsoft: Small fish in a big data center pond.

Microsoft's top expert in building relationships with corporate giants traded Redmond for San Francisco this week to spread the gospel to local sales teams as the company adapts to a new and unfamiliar role: the underdog.

The consumer software and operating system titan has rolled out a server strategy designed to topple Sun Microsystems, H-P, Oracle and IBM from their perches as providers of data centers for big companies.

Vice President of Enterprise Business Relations Bob McDowell addressed two groups of sales people -- several of whom are reportedly working with Chevron and Solectron now -- encouraging them to revamp their mindset from selling packaged products to "providing …