Microsoft's leaders really, really want you to forget about Vista and move right on to Windows 7. And who can blame them? Vista was a train wreck. No one who knows what they're doing runs Vista, not even the Microsoft faithful. Windows 7, on the other hand, is a worthwhile desktop operating system. There's only one little problem. There's no good way to get from XP to 7.

Actually, that's not a small problem at all. According to Net Applications' Market Share report, in August 2009, 71.7% of all desktops were running XP, compared to a mere 18.8% running Vista. So, that means the great majority of Windows users will have to try to migrate from XP to 7.

I use the word "migrate" deliberately instead of "update" or "upgrade" because this will be a migration. If you are among the small minority using Vista, you can upgrade to 7 without any fuss or muss, so long as the move is between equivalent versions, like Vista Home Premium and Windows 7 Home Premium, or you're jumping up, to Windows 7 Ultimate, for example.

I only wish that were the case for XP. The only way you can get from XP to Windows 7 is to do a clean install. Period. End of statement.

And, what's involved with a clean install, you ask? It means you erase every last program and file on your hard disk during the "upgrade." Ow.

You can save some of it. Microsoft's Windows Easy Transfer, which comes in Windows 7, will let you save your files and your settings. Of course, some of those settings may not work anymore with Windows 7, but that's a relatively minor pain.

The major headache is that you can't transfer your old programs and device drivers from XP to Windows 7. So, do you know where your install disk is for Quicken 2008? How about Office 2003? Or, for that matter, do you really want to download iTunes and Firefox, plus a half-dozen must-have Firefox extensions, all over again? Well, you'd better know what you have on your current XP system, and you'd better be ready to reinstall them all and reset them to just the way you like them, because that's exactly what you're going to need to do.

For an individual, that's annoying. It took me two or three hours, but I'm always installing and updating operating systems. Microsoft estimates that heavy users, people with 125GB of data and 40 applications, would need between 2 hours and 40 minutes and 5 hours and 43 minutes to upgrade their systems. A super user could take close to 20 hours But, wait, those Microsoft numbers are for Vista to Windows 7! XP to Windows 7 can only take much longer. At best, I suspect we're looking at it taking a full day for heavy users to make the migration.

Now, imagine multiplying that by a business's dozens to tens of thousands of PCs. That's not just a headache; it's the kind of major suffering that companies try to avoid whenever humanly possible.

Full story: ComputerWorld