Microsoft reiterated on Friday that companies still using Windows NT Server 4 going into 2005 will have to sign up for a custom contract to get support.
Microsoft is offering up to two years of custom support to companies still using the OS when Microsoft ceases its extended support for the program at the end of 2004.
The company has decided to expand the for-free programme to cover more security issues. Microsoft is now pledging to offer fixes for vulnerabilities rated either as "critical" or "important". Previously, the software maker had only committed to fixing critical flaws.
Those fixes will be available only to those that take part in the paid custom-support programme, though Microsoft has said it would offer a patch publicly were there to be another virus on the order of Blaster.
"We will act to protect the integrity of the Internet," said Peter Houston, senior director of Windows serviceability.
At the same time, the company stressed that it is not changing the 31 Decmber end-of-life date for NT 4 Server. The desktop version of NT 4 reached end of its life in June.
"My recommendation is that if you haven't done so already, begin your migrations immediately," Houston said. Those who need more time should take part in the custom service programme, he said.
After spending much of this year talking to customers, Microsoft has decided to commit to offering the custom support for up to two years, though customers can purchase as little as three months' worth -- an incentive for those that migrate quicker. The company has been trying to convince as many customers as possible to upgrade to newer versions, offering, among other things, a step-by-step migration guide on its Web site.
Microsoft would not say how much the programme costs but said it is a flat fee regardless of how many servers a company has, with the fee based on the length of the contract.
Houston said he did not know the exact number of customers that have signed up for the custom support programme, but he said it is on the order of 100 -- mostly businesses and government agencies that are among Microsoft's largest customers.
Microsoft also said Friday that it will offer a similar plan for its Exchange 5.5 email server software when that programme ends extended support at the end of 2005. Custom support for that program will run through the end of 2007.
