Sorry, but it's just too early to say that Windows 7 Upgrade Chaos Looms. There could be pain, perhaps, but any OS change or upgrade is going to be be tough. After experimenting with the Windows 7 pre-beta distributed at the PDC, I'm somewhat optimistic.Even at its pre-beta stage, Windows 7 is better than Vista. Lacking any high-end hardware to use for testing, I decided to install it on a five-year-old XP white-box system. This system isn't a slug -- 2-GHz Pentium 4, 1-GB RAM, 80-GB drive, ATI All-In-Wonder graphics -- and it's probably typical of a lot of older systems that companies have deployed. If Windows 7 can make it here, it can make it anywhere.

I was pleasantly surprised how well Windows 7 ran on this system. It was quick and responsive, even with the default Aero Glass theme enabled. The new UAC is much less annoying and intrusive than Vista's version. There were a few glitches, but given that this isn't even a true beta I'm fine with cutting Microsoft some slack until a later beta applies. My take at the moment is that both Vista and XP users could be comfortable with Windows 7.

For those predicting chaos, recall that Windows XP support will end in a few years. Companies will need to go somewhere in their post-XP world. My question would be, exactly what choice minimizes the chaos? If Windows 7 doesn't fit your plans, perhaps you can listen to the "switch to Linux" or "buy a Mac" crowd to support a large business.

The Mac solution has guaranteed maximal chaos and price; you'll need to throw out all your existing hardware and software, then pay top dollar for Apple systems. That won't happen overnight, so you'll be supporting both PCs and Macs for years as the company transitions out the PCs. Don't forget training, either. All the IT staff and users will need to come up to speed with Apple's way of doing things.

With a Linux solution, at least you can salvage the PC hardware and corporate investment in it. New hardware costs are likely to be much lower as well, compared with Apple's prices. The training and learning costs of switching to Linux aren't trivial, though, and there's no guarantee that the internal applications you may have built (for example, Excel macros and spreadsheets) will be able to follow you to Linux.

Every company's needs are different, of course, and perhaps a Mac or Linux really could fit the bill for some of them. It's more likely that the IT department of any moderately large corporate PC network is going to find Windows 7 is the least chaotic of the available choices.