More than half of British SMBs may be forced to replace their IT infrastructure by July 2015 because they run on Windows Server 2003, it is claimed.
Microsoft is due to retire support for its server operating system on July 14, 2015 - marking today as the last year critical patches and updates will be issued for it.
A Cloud Industry Forum (CIF) survey of 250 IT decision makers found that 53% run the Server 2003 OS, despite Microsoft's recent efforts to persuade firms to migrate to Server 2012, but 69% see cloud as an attractive way to refresh their infrastructures.
Three-quarters of respondents had adopted the cloud, but half of those use it for just one service, and 86% rely on both cloud and on-premise technology.
Nick East, CEO of cloud-managed server specialist Zynstra, said: "Those with Windows 2003 server still running should act soon to ensure a smooth transition before support ends.
"Businesses can use the opportunity of infrastructure refresh to deliver better value from their IT estate. SMBs are clearly already favouring a hybrid approach. Our view is that nine out of 10 companies will continue to invest in on-premise IT alongside and integrated with remote cloud solutions."
Server 2003 is one of several Microsoft products for which support will end in 2015.
Windows 7, Windows Server 2008 and Windows Storage Server 2008 will reach end-of-life on January 13, 2015, among other tools.
A Microsoft blog post in June said the average Windows Server takes more than 200 days to migrate.
Steve Brennan, Microsoft business development manager at QA, wrote: "As you migrate your IT infrastructure to Windows Server 2012 you benefit from reduced cost of ownership through the improvement of management of resources, better security, high scalability, improved performance, increased functionality, in-box virtualisation and cloud support, improved manageability and on-going product support."