The "vast majority" of organisations are running unsupported versions of Microsoft Office, according to Spiceworks.
The IT industry network claims that more organisation are running Office XP, Office 2003 and Office 2007 - sacrificing security in favour of balancing their budgets.
Peter Tsai, senior technology analyst at Spiceworks, said: "Although they're aware of the security risks of running end-of-life software, many IT departments have not had the budget, time, or resources required to implement new productivity suites and train end users accordingly.
"However, as IT budgets and staff begin to grow in 2018, more organisations will look to invest in newer cloud-based and as-a-service productivity suites with more resources to manage the transition."
Three versions of Microsoft Office have been released since 2007, as well as Office 365, with Office 2019 set to be released late next year.
The Spiceworks research found that 82 per cent of organisations are using on-premise versions of Microsoft.
Office 2010 is the most commonly used at 83 per cent of respondents, followed by Office 2007 at 68 per cent.
Support for Office 2007 stopped in October last year.
Spiceworks surveyed over 1,100 organisations across the US, the UK and Canada.
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