Upgrading from Windows Vista to Windows 7

More from WSJ's Walt Mossberg on migrating their existing PCs to Microsoft's new edition of Windows, called Windows 7.

If you are currently running Windows Vista, an upgrade is far simpler than upgrading from XP. Unlike migrating from XP, the upgrade from Vista is designed to be relatively straightforward. It’s a direct upgrade process that preserves all your personal files, settings and programs.

However, even this easier transition involves some choices and limitations that can be confusing for mainstream, non-techie users, so I will try to sort them out here. Throughout this column, I will be referring to simple, direct, upgrades meant for average users. I won’t be discussing more complex methods that require things like wiping out, or dividing, hard disks.

Unlike Vista, Windows 7 doesn’t require beefier hardware than its immediate predecessor. It should work fine on nearly every Vista PC, and even on many late-model computers running XP. In fact, it is a bit less demanding than Vista. For instance, Microsoft has repeatedly demonstrated Windows 7 working on low-powered netbooks that choked on Vista.

However, just like Vista, Windows 7 will be sold in a multitude of different editions, and deciding which one to buy can be confusing. There are six different flavors, though one is reserved for countries Microsoft calls “emerging markets.” Of the remaining five, one is for big businesses. Another, a stripped-down edition called Starter, can’t be installed as a direct upgrade for existing computers, according to Microsoft.

Most consumers will likely choose Windows 7 Home Premium, which costs $120 for upgraders and has all the key Windows 7 features. The next step up, called Professional, adds a few extras that may be especially useful for consumers who work at large companies or use older, specialized programs. Most notably, the Professional edition, unlike the Home Premium version, can remotely tap into certain corporate networks that use a system called “Domain Joining.” And the Professional version has the ability to run older Windows XP programs that wouldn’t otherwise work in Windows 7. It costs $200 for upgraders. The other likely choice is called Ultimate. It combines every feature of the other editions but costs upgraders $100 more than Home Premium.

There are limitations on which current Vista machines can be directly upgraded to the various versions of Windows 7. In general, you can only upgrade your current version of Vista to the comparable version of Windows 7. For instance, Vista Home Premium can only be upgraded to Windows 7 Home Premium and Vista Business can only be upgraded to Windows 7 Professional. This rule has two exceptions. Any flavor of Vista except Starter can be upgraded to Windows 7 Ultimate, if you care to spend the extra money. And Vista Home Basic can be upgraded to Windows 7 Home Premium.

All of the three common consumer versions of Windows 7 can run inside virtual machines, such as the faux Windows computers created on Apple Macintosh hardware using the Fusion and Parallels software. However, the upgrade rules still apply.

After you’ve installed Windows 7, you can move up from Home Premium to Professional with minimal extra effort, for an added sum, by using a program from Microsoft called Windows Anytime Upgrade. This unlocks the added features of Professional, which were actually already on your machine, but were hidden. You can do the same thing to move up to Ultimate.

However, there’s another complication. For each of the three main consumer versions of Windows 7, there are actually two editions. One is meant for PCs with standard processors, called 32-bit processors, and the other for PCs that sport newer processors called 64-bit processors. The 32-bit version of Windows can recognize only 3 gigabytes of memory, but the 64-bit version can use much, much more. For most average users, 3 gigabytes is plenty, but some consumers have 64-bit Vista machines, which can move faster when lots of programs are being used at once, or when doing tasks like playing back high-definition video.

The problem is that you cannot directly upgrade 32-bit Vista to 64-bit Windows 7, or vice versa. So that adds another layer of complexity to the upgrade process.

Finally, a note about prices. Most major Windows PC makers are offering free, or very low cost, upgrades to Windows 7 later, if you buy a Vista PC now. They are doing this, in cooperation with Microsoft, to discourage people from waiting until October to buy a new PC. Each hardware company has slightly different policies on this. However, this free upgrade program isn’t of any help if you simply want to keep your existing PC and upgrade it to Windows 7.

You can learn more about the various editions of Windows 7 at: windows.microsoft.com/en-us/windows7/products/compare-editions?T1=tab01. And I’ll have a full review closer to its Oct. 22 release date.

—Find all of Walt Mossberg’s columns and videos online, free, at the All Things Digital Web site, walt.allthingsd.com. Email him at mossberg@wsj.com Printed in The Wall Street Journal, page A29