Computer security firm Symantec warned that users of Microsoft's new 'Vista' operating system could find their options for running anti-virus style software seriously reduced.

Vista is still in the final stages of its development phase and the system is not due to go on sale until the beginning of 2007.

But Symantec's communications director Chris Paden on Wednesday told AFP that in its current form the new Microsoft operating system (OS) would "reduce consumer choice" when it came to computer security.

The problem, Paden explained, was that Vista currently contains a built-in Microsoft 'security centre' that includes applications such as anti-virus software, firewalls and anti-spyware packages.

Security Centres have existed in previous Microsoft systems -- there is one in the popular Windows XP for example -- but until now it has always been possible to replace the Microsoft package with security software made by another company.

With the current version of Vista this will not be possible, Paden said. It will be possible to install other security packages but not remove the Microsoft centre.

"It would be like trying to drive a car with two dashboards. This is going to cause a great deal of consumer confusion," Paden complained.

As the world leader in security software, Symantec clearly has a vested interest in ensuring it is possible to install non-Microsoft security packages in Vista.

But the Symantec spokeman insisted his complaints were not solely motivated by self interest. He said Microsoft should try to promote the development of new and better software by allowing other companies' products to work easily with Vista.

"If they really wanted to promote innovation, they would work with vendors," he said.

He accused Microsoft of "digging their heels in" and refusing to listen to Symantec's request for Microsoft to make it possible to remove the built-in security centre from the new operating system.

He also warned that Vista users could face serious computer security problems as the new operating system had not been designed to take into account the latest generation of security threats.

The European Commission, which in March 2004 slapped a record fine of 497 million euros (631 million dollars) on Microsoft for abusing its dominant market position, has already warned the software giant that in its current form Vista risks falling foul of EU competition rules.

In March this year EU Competition Commissioner Neelie Kroes said the new operating system could break competion law, notably because of its security compnents.

Since then, Microsoft and the Commission have been in discussions over the issue.