Windows 7 — Microsoft's seventh incarnation of its market-leading computer operating system — is now available, and like each previous version of Windows, it is more evolutionary than revolutionary.

So if you're part of the 92 percent of computer users whose PC is powered by Windows, should you make the switch?

First, let me say that I've not yet had a chance to use Windows 7. I tried installing a pre-release version on an ailing Vista-based PC, but the installation didn't work.

Everything I've read in credible technical publications would seem to indicate that Windows 7 is a worthy upgrade because it addresses some shortcomings of Windows Vista and it is designed to operate smoothly on a wider variety of hardware.

If you're buying a new Windows PC, chances are you won't even have a choice; it will come with Windows 7 installed.

If you've purchased a new computer in the last few months, there's a good possibility that the manufacturer has included an offer to get a free or low-cost copy of Windows 7 for you to install yourself. If this is the case, I suggest that you take advantage of the deal, but hold off on installation for a few months in case there are any major problems that have to be fixed after the software is widely deployed.

When you get the upgrade from the manufacturer of your computer, you can have some assurance that it has been tested on your specific computer configuration, and that it comes equipped with any necessary software and hardware "drivers" needed for everything to work smoothly. You also may qualify for free technical support in case you run into problems.

But what if you have an existing PC and want to upgrade to Windows 7? Microsoft has developed an upgrade advisor tool that will evaluate your hardware and software and make a suggestion.

Generally speaking, the older your computer, the less likely it is to be a Windows 7 candidate, although Win 7 is designed so that some of its more advanced functions can be dialed down to accommodate PCs with slower processors and less memory.

Almost any computer running Vista should be a safe bet, because Windows 7 is derived from Vista. If you have Windows XP on your computer, it's a trickier situation because — even if your machine has the necessary horsepower — you can't perform an "upgrade." You are limited to a "clean install," which means you'll have to reinstall all existing software after Windows 7 launches (do you know where all those disks are now?). Not an appetizing proposition for most users.

There is one other thing to consider if you're tempted to upgrade to Windows 7: Which version to get?

Should it be Home Premium ($120), Professional ($200) or Ultimate ($220)?

Microsoft's handy chart outlines the options. Home Premium, as the name suggests, should be satisfactory for most families. Professional includes some networking options suitable for business users, and Ultimate incorporates data security functions and multiple language capabilities.

My recommendation for everyone is really just common sense: If your computer is working well for you, there is no compelling reason to switch to Windows 7 immediately.

If you have an older computer that has is hovering around the minimum specifications for Windows 7, you might consider applying the cash you would invest in the operating system toward a new PC with Win 7 built-in. You might be surprised at how much computer you can get for $400 or less, especially if you already have a suitable monitor.

My work computers continue to run Windows XP, but I just purchased a new home computer that came with a Windows 7 upgrade option. I'll be using this to evaluate the installation and operation of Microsoft's new operating system in the weeks and months ahead.

Watch this space.

E-mail askwalt@wfaa.com