Windows 7 : Hardware and Software Compatibility (part 5) - Windows Virtual PC and XP Mode - Understanding Windows Virtual PC

2. Windows Virtual PC and XP Mode

When all else fails, a new Windows 7 feature can come to the rescue. Actually, there are two features involved:

• Windows Virtual PC is a software solution that provides a virtual machine environment in which guest operating systems, with their own applications and services, can run separately and independently from the host environment, or physical PC.

• XP Mode provides a virtual version of Windows XP in which you can configure virtualized, XP-based applications to run side by side with native Windows 7 applications. This effect is shown in Figure 11.

  Figure 11. It's crazy but it's true: Windows XP and Windows 7 applications can now run side by side.

  

The next sections take a look at both of these new Windows 7 components.

4.2.1. Understanding Windows Virtual PC

To the operating system and applications running in a virtual environment like Windows Virtual PC, the virtual machine appears to be a real PC, with its own hardware resources and attributes. These virtualized systems have no knowledge or understanding of the host machine at all.

Though virtual machines cannot rival the performance of real PCs for interactive use—they're useless for graphically challenging activities such as modern, action-oriented games, for example—they are perfect for many uses. In fact, virtual machines are often used to test software in different environments, or test Web sites and Web applications with different browser versions.

In Windows 7, the Windows Virtual PC virtualized environment—shown in Figure 12—plays a special role. Because new versions of Windows are often incompatible with legacy applications, a virtual machine environment running an older version of Windows and those incompatible legacy applications can be quite valuable. Best of all, in such cases, users are often less apt to notice any performance issue because older operating systems tend to require fewer resources anyway.

Figure 12. Here, you can see Windows XP running inside Windows Virtual PC on top of Windows 7.

That said, for the best results, anyone utilizing Virtual PC to run an older operating system such as Windows XP along with whatever set of Windows 7–incompatible applications is well served to pack the host PC with as much RAM as physically possible. For typical PCs today, that means loading up with 4GB. Remember: you're running two operating systems and any number of applications simultaneously. That old Pentium 3 with 256MB of RAM just isn't going to cut it.

NOTE

Windows Virtual PC has specific hardware requirements, and thanks to the vagaries of microprocessor marketing, your PC may not be up to snuff. The only important consideration, indeed, is the microprocessor: in order to run Windows Virtual PC (and, thus, XP Mode as well), you need a microprocessor that supports hardware-assisted virtualization. And you must be able to enable this functionality in the PC's BIOS. If you don't have such support, you'll see the error message shown in Figure 13 when you try to install Windows Virtual PC.

Figure 13. Windows Virtual PC has very specific hardware requirements and won't work on all PCs.

This technology goes by different names depending on which microprocessor vendor you're talking about. With Intel, it's called Virtualization Technology (Intel VT). And with AMD it's simply called AMD Virtualization (AMD-V). The vast majority of modern (for example, 64-bit and multicore) AMD processors include AMD-V, so you're generally in good shape if you're running a PC with an AMD processor. But in the Intel world, you have some work ahead of you.

Let's get the simple part out of the way first. If your PC utilizes an Intel i7 or i7 Extreme processor, you're all set. All of these products include the necessary hardware support. For the remainder of Intel's modern CPU lineup, however, you can refer to Tables 1 and 2.

Table 1. Intel Desktop Microprocessor Support for Hardware-Assisted Virtualization

Intel Microprocessor	Supports Hardware-Assisted Virtualization
Core 2 Duo E4300, 4400, 4500, 4600, and 4700	No
Core 2 Duo E6300, 6320, 6400, 6420, 6540, and 6550	Yes
Core 2 Duo E6600, 6700, 6750, and 6850	Yes
Core 2 Duo E7200, 7300, 7400, and 7500	No
Core 2 Duo E8190	No
Core 2 Quad Q6600 and 6700	Yes
Core 2 Quad Q8200, 8200S, 8300, 8400, and 8400S	No
Core 2 Quad Q9300, 9400, and 9400S	Yes
Core 2 Quad Q9450, 9550, 9550S, and 9650	Yes
Pentium D Pentium EE 805, 820, 830, and 840	No
Pentium D Pentium EE 915, 925, 935, and 945	No
Pentium D Pentium EE 920, 930, 940, 950, and 960	Yes
Pentium D Pentium EE 955 and 965	Yes
Pentium for Desktop E2140, 2160, 2180, 2200, and 2220	No
Pentium for Desktop E5200, 5300, and 5400	No

Table 2. Intel Mobile Microprocessor Support for Hardware-Assisted Virtualization

Intel Microprocessor	Supports Hardware-Assisted Virtualization
Core 2 Duo Mobile L7200, 7300, 7400, and 7500	Yes
Core 2 Duo Mobile P7350, and 7450	No
Core 2 Duo Mobile P7370	Yes
Core 2 Duo Mobile P8400, 8600, 8700, 9500, and 9600	Yes
Core 2 Duo Mobile SL9300, 9400, and 9600	Yes
Core 2 Duo Mobile SP9300, 9400, and 9600	Yes
Core 2 Duo Mobile SU9300, 9400, and 9600	Yes
Core 2 Duo Mobile T5200, 5250, 5270, 5300, 5450, and 5470	No
Core 2 Duo Mobile T5500, and 5600	Yes
Core 2 Duo Mobile T5550, 5670, 5750, 5800, 5850, 5870, and 5900	No
Core 2 Duo Mobile T6400, and 6570	No
Core 2 Duo Mobile T7100, 7200, 7250, 7300, and 7400	Yes
Core 2 Duo Mobile T7500, 7600, 7700, and 7800	Yes
Core 2 Duo Mobile T8100, and 8300	Yes
Core 2 Duo Mobile T9300, 9400, 9500, 9550, 9600, and 9800	Yes
Core 2 Duo Mobile U7500 and U7600	Yes
Core 2 Extreme Mobile QX9300	Yes
Core 2 Extreme Mobile X7800 and 7900	Yes
Core 2 Extreme Mobile X9000 and 9100	Yes
Core 2 Quad Mobile Q9000	Yes
Core 2 Quad Mobile Q9100	No
Core 2 Solo SU3300 and 3500	Yes
Core 2 Solo U2100 and 2200	Yes
Core Duo L2300, 2400, and 2500	Yes
Core Duo T2050 and 2250	No
Core Duo T2300, 2400, 2500, 2600, and 2700	Yes
Core Duo T2300E, 2350, and 2450	No
Core Duo U2400 and 2500	Yes
Core Solo T1300 and 1400	Yes
Core Solo T1350	No
Core Solo U1300, 1400, and 1500	Yes

If the PC you're using does not include a microprocessor that supports hardware-assisted virtualization, you have two options: you can use a different PC, of course. Or you could use a competing virtualization solution that doesn't include such a limitation. (Note, however, that no competing virtualization products include a free copy of Windows XP.) We favor VMWare Workstation (www.vmware.com/products/ws) but if you would like a free solution, check out VirtualBox (www.virtualbox.org) instead.

NOTE

If your PC's processor has hardware-assisted virtualization support but you failed to enable it in the BIOS, you will see the dialog shown in Figure 14 when you attempt to install XP Mode or another OS in a virtual machine. That means you have to reboot, enable the feature in the BIOS, boot into Windows again, and then rerun Windows XP Mode Setup. So get this set up first.

Figure 14. Enable hardware-assisted virtualization before running XP Mode Setup or configuring any other virtual machines.

You manage Windows Virtual PC from a very simple Virtual Machines explorer, rather than from the console application window that accompanied previous versions. Shown in Figure 15, this window provides a toolbar button from which you can create a new virtual machine.

The Create a virtual machine wizard (see Figure 16) can create new virtual environments using an existing virtual disk, or, more likely, by creating a new one from scratch. In the latter case, you install a new operating system just as you would normally, using the original setup CD or DVD, or an ISO image, which can be "mounted" so that it works like a physical disk from within the virtual environment.

After determining the name of the virtual machine, how much RAM it will use, and the location of the virtual hard disk, it's time to install an operating system. You're welcome to install virtually any modern, 32-bit version of Windows, but Windows Virtual PC natively supports Windows 7, Windows Vista with SP1 or higher and Windows XP with SP3 in a special way: in these environments, you can install integration components that take guest-to-host integration to the next level.

Figure 15. Console be gone: Windows Virtual PC is managed from a simple explorer.

Figure 16. Virtual PC's Create a virtual machine wizard helps you determine the makeup of the virtualized environment.

Noticeably absent from this list, incidentally, is any form of Linux. You can, in fact, try to install various Linux distributions in Windows Virtual PC, but this install type has some limitations, chief among them a lack of integration with the host environment that supported guest operating systems receive. That said, many modern Linux distributions don't work correctly in Windows Virtual PC unless you are capable of some serious tinkering. In this case, Google is your friend.

To manage any virtual machine environment you've created, just select it in the Virtual Machines explorer and click the Settings button that appears. The resulting Settings window (see Figure 17) lets you configure individual VM settings, including the RAM, virtual hard disk(s), and other devices associated with the VM.

In use, virtual machines are like slower versions of "real" PC installs. You can continue running guest operating systems in a Windows Virtual PC window side by side with the host Windows 7 system, or you can run the guest OS full-screen, making it appear as if your modern Windows 7–based PC has gone back in time. Windows Virtual PC supports a variety of niceties for moving information back and forth between the host and guest operating systems, including cut-and-paste integration and the notion of a shared folder that exists in both systems so you can move files back and forth.

But what really makes Windows Virtual PC special is that those integration components allow compatible operating systems to publish their applications into the host PC environment. That way, you don't have to launch and manage a second PC desktop. Instead, you can simply use the application(s) that caused you to install Windows Virtual PC in the first place.

Figure 17. Individual virtual machines are managed with a single window too.