Customer concerns over changes to Windows Vista licensing that would limit a transfer of the licence to only one machine have moved Microsoft to revise the policy.

Microsoft said today it has changed the retail licence terms for Vista so that customers may now uninstall the OS (operating system) from one machine and install it on another as many times as they want. The new terms do away with limitations on the number of new devices to which the licence can be transferred.

However, to continue the discouragement of piracy, Microsoft has worded the licence so that it's clear that users cannot "share this licence between devices".

When the new licensing was disclosed several weeks ago, power users who rebuild their computers with new components several times a year or who plan to upgrade their computers more than once in the lifetime of the OS raised a fuss. They demanded clarification from the vendor about how scenarios like these would play out under the new licensing.

According to Shanen Boettcher, Windows general manager at Microsoft, the company thinks it has come up with an answer to placate those users without encouraging software piracy, which the original change was designed to thwart.

"We think this clarification strikes the right balance," he said. Boettcher claimed the piracy problem has nothing to do with "the enthusiast community that was sending me emails", but with people who install one licensed copy of Windows on many machines and then sell those to other users.

"This is a definite improvement over the original licensing terms, and I'm glad Microsoft has relented," says Don Smutny, a Windows user and software developer for a large IT company in US. However, he is still not convinced there aren't other hidden complications within Vista's licence that will have to be addressed later.

The change in policy will not affect consumers who purchase their Windows licence preinstalled on a PC from a hardware manufacturer. No licence transfers are allowed in those cases.

Information about licensing changes for any Microsoft product is available on Microsoft's site, though Vista details may not be available right away.