All of the new features and functionality in Windows 7 are pointless if the system doesn't work with the hardware devices and software applications you already own. Likewise, if the PC crashes or experiences other unreliable behavior, good vibes about new features and user experiences will quickly dissipate. In keeping with its tactics on past Windows versions, Microsoft has imbued Windows 7 with a host of compatibility and reliability functionality. Most of this stuff works in the background and rarely needs to be manually accessed by the user. But it's nice to know that it's there, and if you ever do need it, chances are that Windows 7 can come to the rescue and right the wrongs.

Compatibility

Compatibility has always been a two-edged sword in Windows. On the one hand, Microsoft's strident belief that it must as fully support legacy hardware and software as well as possible has made the system a safe bet for consumers and businesses around the world. And of course Microsoft's business customers, in particular, demand a certain level of downlevel compatibility; attempting to engineer a version of Windows that wasn't broadly backwards compatible would make that system a non-starter with one of Microsoft's most important customer groups.

In some ways, that's exactly what happened with Windows Vista. When that OS first shipped to business customers about three years ago, if offered excellent compatibility with the mainstream software applications of the day and good-to-excellent compatibility with mainstream hardware. But that wasn't good enough for enterprises, which found poor compatibility with custom applications and the line of business (LOB) applications that drive their companies. As a result, Vista got off to a slow start with big business. In fact, it never recovered.


Businesses might have ignored Vista, but Microsoft steadily improved the Vista compatibility picture, most obviously with Service Pack 1 (SP1). For Windows 7, the software giant realized it couldn't make the same mistake. So Windows 7 shares a compatibility model with Windows Vista with Service Pack 2, the latest Vista service pack at the time of this writing. Unlike when Vista first shipped, Windows 7 is broadly compatible with all of the hardware and software that's currently being sold and used in the market.

Of course, that doesn't mean you aren't going to run into compatibility issues. Windows has changed a lot over the last eight years, and there will always be discontinued hardware that's no longer supported by up-to-date drivers, and esoteric and older software that, for whatever reason, won't run natively under Windows 7. So Microsoft's latest OS includes enhancements to the compatibility technologies that it had previously developed as well as brand-new compatibility solutions that, combined, should pretty much obviate any compatibility concerns.

Consumers and businesses alike should take advantage of the most up-to-date compatibility analysis tools that Microsoft makes available. For individuals, that tool is called the Upgrade Advisor, and as its name suggests, it can help ensure you that your current PC is fully compatible with Windows 7. (As a blanket statement, if you're currently running Windows Vista, you should have no issues with Windows 7.) Business users can take advantage of even more impressive and full featured tools, such as the Application Compatibility Toolkit (ACT) 5.5, which can evaluate application compatibility issues across your entire environment.

Once you're up and running in Windows 7, a familiar set of tools will help you overcome hardware and software compatibility issues. An application compatibility infrastructure lets you run incompatible applications (and application installers, which is often even more important) as if you were using an older version of Windows (dating all the way back to Windows 95). You can access this functionality manually via the EXE's property sheet or, as would be more typical for normal users, via a friendlier Compatibility Troubleshooter wizard.


The Program Compatibility troubleshooter.

As with previous Windows versions, Windows 7 monitors the compatibility of the applications and devices you install and optionally provides feedback to Microsoft so that common issues can be fixed first. And Windows Update will deliver newer drivers when they become available.

Occasionally, even Windows 7 can't solve all your compatibility issues. In these rare cases, Microsoft provides virtualization solutions that allow you to access legacy applications and even legacy hardware devices via a virtualized instance of a previous Windows version. Businesses on Microsoft's Software Assurance (SA) volume licensing program can access a service called Microsoft Enterprise Desktop Virtualization (MED-V), which has been recently enhanced for Windows 7. MED-V is centrally managed and eschews the need for a second virtualized desktop by providing direct access to virtualized applications in the host (physical) environment. These virtualized applications run side-by-side with native Windows 7 applications, which is exciting enough. But they can also access the underlying resources of the host system directly, including the file system (My Documents folder and so on), installed printers, and the like.

For individuals and small businesses, Microsoft has created a non-managed version of MED-V that it is providing for free to all users of Windows 7 Professional, Enterprise, and Ultimate. It's called Windows XP Mode, and it is a fully-licensed and free version of Windows XP with SP3 that runs under Windows Virtual PC (the latter of which is being made available to all Windows 7 users for free, as a separate download). With XP Mode, you can install legacy applications (and legacy hardware) under the virtualized XP version and then access them from within the host (Windows 7-based) desktop. Virtualized XP applications run side-by-side with native Windows 7 apps and, as with MED-V, access the underlying system resources of the host system as well.


Windows XP Mode lets you run XP applications side-by-side with Windows 7 applications.

Generally speaking, XP Mode works incredibly well, if you need such a thing. (Though it's worth nothing that most often, you will not.) And Windows Virtual PC's virtual-to-host integration features are not just limited to XP; you can also achieve such integration with virtualized instances of Windows Vista and 7, though I'd imagine there won't be much need for that.

While XP Mode itself works well, Windows Virtual PC has two notable limitations. Though it is not hypervisor-based, it requires that hardware-based virtualization functionality be present and enabled in the processor and BIOS on the host PC. And it can only be used to create 32-bit guest operating system installs. (This is not an issue for XP Mode, of course, but it makes Windows Virtual PC less viable for those that wish to virtualized other OSes.)

Reliability

As a fundamental part of the operating system, reliability technologies and improvements appear throughout Windows 7. Starting with the low-level changes, Windows 7 utilizes a driver sandboxing model to help prevent poorly-written device drivers from affecting other drivers or the overall Windows OS. Poorly written drivers are, of course, the number one cause of blue screens and other crashes, so this is a big deal.

Because 15 percent of PC crashes overall are caused by heap corruption, Windows 7 has been engineered to include a fault-tolerant heap, which Microsoft says dramatically reduces the cases in which an errant application can cause a crash.

Reliability Monitor has been enhanced in Windows 7 to be more reliable and in to monitor its own reliability. As with Windows Vista, you can opt into Microsoft's Customer Experience Improvement Program (CEIP), and help make Windows better for everyone. But in Windows 7, Reliability Monitor collects more granular system information than did Windows Vista, making the information reported to Microsoft (and to you) all the more valuable. (Microsoft says that information about third party programs is sent to its partners so that they can improve their own products as well Circle of life, people, circle of life.)


Windows 7's Reliability Monitor is as brutal as Vista's, punishing the system score for each transgression.

While Windows Vista included an excellent Windows Backup utility, it worked inconsistently across product editions. This has been improved dramatically in Windows 7. Now, Windows Backup provides both image-based, full system backups as well as targeted file backups, regardless of which product edition you're using. And if you're using Windows 7 Professional or higher, you can perform these backups over the network to a NAS device or other network-based location. (Including another PC; on Windows 7 Home Premium, you can use a second partition, hard drive, or USB-based removable storage device. Windows Backup lets you restore individual files, folders, or all personal files, too, which is excellent.


In Windows 7, Windows Backup now works consistently across all product editions.

Windows 7 also includes an improved System Restore utility, which adds more information about what's changing with each restore and integration with Windows Backup. But I think it's an indication of Windows' improved reliability over both Windows Vista and 7 that I've almost never had to actually access this utility. In Windows Me and XP, System Restore was certainly more commonly used.

For all of these changes, the most obvious reliability feature in Windows 7 may just be the new Action Center, which replaces the Security Center from Windows XP and Vista. Action Center isn't just a new name, however: While it does still provide a central location for managing the security functionality of the OS, in Windows 7 it also provides a front-end to your PC's maintenance status. Put another way, over 50 percent of what Action Center does is related to reliability.


No longer confined to monitoring only security features, Action Center provides an excellent front-end to reliability information as well.

As such, Action Center integrates with some of the reliability features I mentioned previously, including Windows Backup. It also integrates with time-tested Windows features like Windows Update and problem reporting. But in Windows 7, Microsoft has taken reliability to the next level with a new troubleshooting infrastructure called Windows Troubleshooting that works in two ways. First, it waits under the covers for a problem to emerge and then attempts to resolve that issue, sometimes without much if any user interaction. Second, Windows Troubleshooting provides access to numerous built-in troubleshooters, which are wizard-based tools that walk you through the process of identifying why something isn't working as expected and then helping you resolve the issue. Also, it's worth noting that Windows Troubleshooting is extensible, so hopefully PC makers and application developers will create troubleshooters for their own products.

What you get in Windows 7 is troubleshooters around five broad categories: Programs, hardware and sound, network and Internet, appearance and personalization, and system and security. But there are over 20 actual troubleshooters, and all of them serve obvious needs, such as figuring out why you can't connect to the Internet, play a DVD movie, play sounds, and the like.


Windows Troubleshooting provides wizard-based access to Windows 7's excellent troubleshooting tools.

Finally, I should call out Startup Repair. In Windows Vista, it was possible to manually install Startup Repair functionality on the hard drive, or you could access the system recovery tools via the Setup DVD if you had it handy. In Windows 7, this process is simplified, and automatically: Now, Startup Repair is installed automatically on the PC's system partition so you can always access it. This front-end provides access to a number of useful utilities that can do such things as fix a non-booting system and de-corrupt the Registry.

Final thoughts

Windows 7 offers excellent compatibility with the hardware devices and software applications that are in broad use today. And it offers some interesting solutions for those who wish to utilize legacy software applications and even devices. The most notable of these, of course, is XP Mode, a fully-licensed and free version of Windows XP with SP3 that is given to any customer running Windows 7 Professional, Enterprise, or Ultimate. Too, Windows 7 is the most reliable version of Windows yet created. And while most of its reliability functionality consists of updated technology from previous Windows versions, new reliability features like Action Center and Windows Troubleshooting speak to this system's reliability prowess. When they just work, compatibility and reliability get no credit at all. With Windows 7, you can expect not to worry about these issues very much at all.

Continue to Part 12: Wrapping Up...