Understanding hardware and software for 64-bit Windows
If you're trying to decide between a PC running a 32-bit version of Windows 7 or one with a 64-bit version of Windows 7, you might be concerned about the difference between 32-bit drivers and programs and 64-bit drivers and programs.
There's no need to worry. Simply put, a computer running a 64-bit version of Windows 7 needs 64-bit drivers for all your hardware and devices. A driver is software that allows your computer to communicate with hardware devices. Without drivers, the devices you connect to your computer or install inside your computer won't work properly. In most cases, Windows can automatically find and install those 64-bit drivers for you by searching a huge database of drivers included in Windows and using Windows Update.
Unlike drivers, most programs designed for 32-bit versions of Windows work just fine on computers running a 64-bit version of Windows. (Notable exceptions are antivirus programs and so-called utility programs, where you might need a 64-bit version.)
If you have a choice of whether to install a 32-bit or 64-bit version of a program, always choose the 64-bit version if you're running a 64-bit version of Windows. Even though the 32-bit version should work with a 64-bit version of Windows, chances are the 64-bit version will perform better, since it was designed for a 64-bit version of Windows.
You don't have to know the details
The number of new PCs that came with a 64-bit version of Windows rose dramatically when Windows Vista was released. But for Windows 7, most new computers are expected to come with a 64-bit version of the operating system. A few PC makers are even shipping all of their new computers with a 64-bit version of Windows 7.
So for more and more PC buyers, the question will no longer be "Should I choose a 64-bit version?" as much as it will be "Is there any reason not to get a 64-bit version?"
The main drawback in the past to running a 64-bit version of Windows was a lack of 64-bit drivers to make all your hardware work properly. But the rapidly rising popularity of 64-bit versions of Windows explains why there are now 64-bit drivers available for tens of thousands of different devices.
If you don't want to know the technical details of 64-bit computing and just want to let Windows do the work for you, you can stop reading here. Windows 7 is designed so you don't even need to know if you're running a 32-bit or 64-bit version of the operating system.
If you want to know what hardware and software issues you might encounter with a 64-bit version of Windows, read on. For more information, check out 32-bit and 64-bit Windows: frequently asked questions.
Let Windows find 64-bit drivers for you
A 64-bit computer is defined as a computer with a 64-bit processor (also called an x64 processor, or CPU) running a 64-bit version of Windows. Most new PCs sold today come with a 64-bit processor, although not all of those computers also come with a 64-bit version of Windows. That's because a computer with a 64-bit processor can run either a 32-bit or 64-bit version of Windows.
So if you see a computer identified as a 64-bit PC, be sure to check if it's also running a 64-bit version of Windows.
A computer running a 64-bit version of Windows needs a 64-bit driver for every piece of hardware installed in it or connected to it. For example, if you're trying to install a video card (graphics card), printer, or other device that only has 32-bit drivers available, it won't install on a 64-bit version of Windows.
After Windows identifies all of your hardware, it tries to find the best drivers. If you're running a 64-bit version of Windows, it looks for 64-bit drivers.
You can set Windows Update to automatically download recommended drivers for your hardware and devices. This is a good way to make sure all your hardware and devices work properly. But even if you have Windows Update set to automatically download and install all important and recommended updates, you still might not be getting all of the updated drivers available for your devices. For more information, see Automatically get recommended drivers and updates for your hardware.
Check compatibility yourself
For hardware makers to earn a "Compatible with Windows 7" logo, their hardware must have drivers for both 32-bit and 64-bit versions of Windows. If you see this logo, you don't have to wonder if the hardware is going to work on a 64-bit version of Windows.
You can check the availability of 64-bit drivers and programs at the new Windows 7 Compatibility Center on the Microsoft website. This can be useful if you're considering buying a new printer, for example, and want to be sure a 64-bit driver is available before you buy it—or if you want to find out if there are 64-bit versions of your favorite programs.
The Windows Vista Compatibility Center also lists the availability of 64-bit drivers for thousands of hardware products, and tells you whether there are 64-bit versions available for thousands of programs.
In general, the newer your hardware, the more likely there's a 64-bit driver for it. Some older devices, however, might not have 64-bit drivers available.
Look for Windows Vista or Windows 7 compatibility
If there's a 64-bit driver available for the 64-bit version of Windows Vista, chances are it will also work fine with the same hardware installed on a PC running the 64-bit version of Windows 7.
The same holds true for 64-bit programs compatible with Windows Vista. They should also work fine on the 64-bit version of Windows 7. The Windows Vista Compatibility Center will tell you which programs are available in a 64-bit version.
In most cases, however, you shouldn't have to look for 64-bit versions of your programs, since, as explained above, most programs designed for 32-bit versions of Windows work just fine on computers running a 64-bit version of Windows.
What if you're not in the market for a new PC, and you just want to find out if your current PC can run a 64-bit version of Windows? Then you should download and install the Windows 7 Upgrade Advisor from the Windows 7 Upgrade Advisor webpage. This program will analyze your computer, create a report telling you if your PC can run Windows 7, and list any known compatibility issues, including whether you can run the 64-bit version of Windows 7.
More memory available—if you need it
The main advantage of computers running a 64-bit version of Windows is their ability to use more memory than a 32-bit version of Windows, even if more memory is installed in the PC. A computer with a 64-bit version of Windows can use more memory—4 GB (gigabytes) or more—than a PC with a 32-bit version of Windows, which is limited to about 3.5 GB or less.
A 64-bit PC with 6 GB, 8 GB, or more memory can outperform a computer with less memory if you keep a lot of programs and files open at once or you perform a lot of memory-intensive tasks, such as editing HD video or playing the latest 3D games.
Even so, few programs today have been designed to take full advantage of the 3.5 GB of maximum memory that you can use with a 32-bit version of Windows. So depending on what you do and what programs you use, there might be no advantage or only a slight advantage to using a 64-bit version of Windows.
The main advantage comes if you keep a lot of programs running at once. For more information, see Taking the mystery out of 64-bit Windows.
Run 32-bit programs on a 64-bit version of Windows
When you run a 32-bit program on a 64-bit version of Windows 7, the program runs in a 32-bit emulation mode, using software to simulate a 32-bit version of Windows 7. This allows 32-bit programs to run smoothly on the 64-bit operating system. But note that programs designed for 64-bit computing might run faster on a 64-bit version of Windows 7.
Certain older programs that won't work on a 64-bit version of Windows 7 might run fine in Windows XP Mode in Windows 7. As the name suggests, this feature allows programs designed for Windows XP to run smoothly in Windows 7. (Some types of programs might not run in Windows XP Mode, such as security software and programs with intensive graphics.) For more information, see Install and use Windows XP Mode in Windows 7.
You can also try changing the compatibility settings for the program, either manually or by using the Program Compatibility troubleshooter. For more information, see Make older programs run in this version of Windows.
The bottom line: Unlike hardware drivers, even older programs designed for 32-bit versions of Windows should work well with the 64-bit version of Windows 7.
Don't hold back
So don't let concerns about 64-bit drivers and programs keep you from moving to a 64-bit version of Windows. Windows 7 is filled with built-in compatibility features and automatic updating capabilities to help you make the move to 64-bit computing. And PCs with 64-bit processors are already outselling PCs with 32-bit processors, causing the number of 64-bit drivers to explode.
With a little knowledge about these hardware and software issues, you won't sweat the move to 64-bit computing.