
The options are available only for Windows Vista Enterprise and limited to enterprises subscribing to Microsoft's Software Assurance programme.
The first change enables the use of the operating system in so-called diskless PCs. This allows enterprises to use a centralised storage facility to save and run the operating system for its desktop computers.
Centralising storage cuts down the cost of managing desktop systems and increases security.
Microsoft's previous licensing system didn't allow the software to run from a shared storage pool. Customers also didn't ask for the option because networking technologies lacked the bandwidth to enable such applications.
The second licencing change allows company to run Windows Vista in an even more centralised way through the use of virtualization on server hardware.
Where a diskless system still requires a CPU in the client computer, this Windows Vista Enterprise Centralised Desktop (VECD) structure allows the software to run with even less overhead on a PC, laptop or thin client.
Microsoft expects that the two new licensing programmes will especially appeal to companies in highly regulated industries. But the firm cautioned that the underlying technology is still relatively young.
"We think that only a select few customers are planning to broadly implement these centralised desktop models today," said Scott Woodgate, director of Microsoft's Windows Business Group.
"The customers that are exploring these new deployment scenarios are early adopters, and they will help prove out the usefulness of centralization over the next few years. The changes we’re making enable them to do that and to see whether their expected benefits pan out in production."