According to Yahoo blogger Christopher Null: The Working Guy

One of the few nice things about Windows Vista is that you can legally choose not to use it. Many versions of Vista include "downgrade" rights, which means that if you have a copy of Windows XP, you can install the older OS on your computer without paying extra.

But how many businesses actually take advantage of this policy? A whopping 35 percent of enterprise customers, according to stats compiled by InfoWorld. That figure includes only those systems that were designed for Vista (and sold with the OS) but which have had XP or another Windows OS installed in its place.

The percentage is surprisingly large and may actually be on the low side since the data comes from a system performance monitoring tool that users can voluntarily installed on your computer and which can't monitor Linux cross-grades. It also calls into question some of the bragging that Microsoft has done over Vista sales: Microsoft proudly trumpets that over 180 million Vista licenses have been sold to date, but it doesn't mention that 60 million of those have dropped back to XP or another OS and aren't even using the OS they paid for. (It's possible that Microsoft doesn't even know the extent of the downgrading issue, but I have to assume that Redmond has known about this all along.)

It's difficult to underestimate what a big deal this is. I've never heard of such a violent rejection of a major operating system (Windows Me is the only thing that even comes close), particularly given that the primary alternative is no longer actually for sale. InfoWorld calls the figure "way out of proportion for even the dramatically unpopular Windows Vista."

Many have downgraded to XP as a stopgap measure to make it through until a new version of Windows arrives, but with Windows 7 already looking tragically like Vista 2.0, the vast number of people still forcibly clinging to their old OS bodes poorly for both Microsoft and for users.

I'm curious if the numbers follow over to general users, not just the enterprise. POLL: Do you have a designed-for-Windows Vista PC? What OS is it running now?

UPDATE from Microsoft: Some additional context on the survey: The study monitors only a very small sample-just 3,000 surveyed machines from an unknown number of source, which means that these users are not necessarily representative of Windows Vista users as a whole, and the article doesn't provide additional information on the methodology used in collecting this data. Major enterprises like Continental Airlines, the United States Air Force and Virgin Megastores continue to deploy Windows Vista seats by the thousands. Just this week CDW, one of the world's largest technology resellers and systems integrators, found in its Windows Vista Tracking Poll that the OS is "gaining traction" among businesses-48% of respondents said their organization is using or evaluating Windows Vista, up from 29% just one year ago.