After Windows 2000 was released to manufacturing in December, over 400 members of Microsoft Corp.’s Windows development team hit the road to spread the word to existing customers.

According to Microsoft lead product manager Craig Beilinson, more than 1,400 small and large enterprises in 28 countries received a free visit from a Windows 2000 engineer to help them understand the new operating system and implement it. They were able to ask in-depth questions about certain aspects of the Windows 2000 code.

James Gillen, manager of technical architecture at Bell Mobility Inc., a Toronto-based wireless carrier, said he was surprised when Microsoft called him with an offer to send a Windows 2000 developer. “Microsoft is not known for opening the kimono,” said Gillen.

In February, Bell Mobility met for several hours with two members of the Windows 2000 development team and received hard-to-get information. As a result, the company may end up rolling out Windows 2000 in parts of its business where it had previously not expected to, said Gillen.

Most of the Windows 2000 team have returned to their jobs, writing code, said Beilinson. But Microsoft is considering a repeat of the program for future product rollouts, he said.

“This is something customers were clamoring for,” said Laura DiDio, an analyst at Giga Information Group Inc. in Boston. “Anything that opens (Windows 2000) up and lets people have a peek under the covers is a good sign.”

Microsoft said the initiative had nothing to do with the rising popularity of the Open Source software model, which contrasts with Microsoft’s policy of keeping its source code under wraps. But Gillen said he had never seen such openness from Microsoft before.