That is the verdict of analysts at Gartner, who said many businesses were skipping Windows Vista, so would have to move to Windows 7 because version 8 remains "nowhere in sight".
Microsoft will not support XP after April 2014, and Gartner advised businesses to make the move off the system well before this date. Additionally, by the end of 2012, many other suppliers' applications will not support XP, it warned.
"In various Gartner polls and surveys, 80 percent of respondents report skipping Windows Vista," said Michael Silver, VP at the firm. "With Windows XP getting older and Windows 8 nowhere in sight, organisations need to be planning their migrations to Windows 7."
Silver noted that many businesses had indicated an interest in moving to Windows 7, but a number are still undecided about when to start and how quickly to make the transition.
Businesses should investigate if their software suppliers provide sufficient Windows 7 support, he said, and to build in 12 to 18 months' planning and testing time before this, in order to decide a reasonable start date.
The analyst house advised businesses to set a clear target date for removing Windows XP, and to decide whether to deploy Windows 7 to all PCs or only to new PCs. But Silver said that even those that plan to make the move when hardware is replaced should set a clear timeline, and be aware that hardware attrition may not be fast enough.
He also warned businesses to weigh up the cost of supporting multiple versions of Windows - as well as the cost to deploy a new operating system to every user, which, for organisations without Software Assurance on Windows, will also include the cost of buying additional upgrade licences.