Microsoft has come under fire from two US war veterans organisations over its decision to call the next version of Windows "Vista".

The VistA Software Alliance and WorldVista, two non-profit groups that assist American veterans hospitals, nursing homes and clinics with its VistA software, have denounced Microsoft's name choice, citing possible confusion between the operating system and the software used to store and manage veterans' patient information.

"The confusion created by Microsoft and its choice of the word 'Vista' is an affront to the people who take care of our nation's veterans," Barbara Boykin, chairman of the VistA Software Alliance said. "The VistA software enables these caring professionals to provide our veterans with some of the best healthcare in the nation. Microsoft is demeaning their passion and dedication to our veterans by expropriating the name Vista."

VistA has been in use for about 20 years and provides electronic records for millions of veterans in 163 hospitals, 135 nursing homes and 850 clinics, according to the groups.

The timing of the naming is especially inconvenient because the Centers for Medicare and Medicaid Services is readying the release of VistA-Office EHR (electronic health record) within a few days, according to the groups. This is a version of VistA specifically tailored for medical practices and will be offered for free or low-cost to physicians nationwide.

Chairman of WorldVistA Maury Pepper called the timing of Microsoft's announcement "unfortunate" and said that it detracts from the nationwide effort to provide VistA to the healthcare industry. Many believe the industry, which still handles much of its information in long paper trails, is long overdue for a standard, electronic system to manage patient data.

A Microsoft spokeswoman said that Microsoft did a thorough search before picking the name to ensure Windows Vista would not infringe on the trademarks of other companies or products. She also said that since the trademarked name is a combination of two words - "Windows" and "Vista," one of which is clearly associated with Microsoft - the name should not create any confusion between the operating system and other similarly named software.

The non-profit groups are not the first to cry foul over Microsoft's naming of its next-generation operating system. Just days after Microsoft's 22 July announcement of the new name, the chief executive officer (CEO) of a consulting and software company in the same town as Microsoft announced he was considering a legal challenge to the name.

At the same time, the leaders of two other companies that provide add-on technologies for Microsoft products and also share the Vista name said separately they were pleased with the name choice.