Those machines are probably running XP, because only 9 percent of nearly 1,000 North American and European businesses surveyed in a recent Gartner report said they upgraded to Vista.

Despite the economy, however, Windows 7 probably won't be as disastrous an OS as Vista was in the business market, analysts and IT professionals said. There are some good reasons to upgrade to Windows 7, even if companies have to scrape the bottom of their budgets to do so.

XP is now eight years old and beginning to show wear and tear, said Andrew Brust, chief of new technology at the IT consulting firm twentysix New York. "It stood the test of time very well, but it is now definitely showing its age," he said.

Even with budgets as tight as they are, companies that can upgrade to Windows 7 should and probably will, because they have waited so long to upgrade, Brust said.

"Many customers probably held off on Vista upgrades, choosing to wait for its successor, so there’s real upgrade backlog to tend to," he said.