Although Windows XP did have a 64-bit version, it wasn’t until Microsoft released Windows Vista that consumers really had to make a decision of whether to buy the 32 or 64-bit version.
Windows 7 also comes in 32 and 64-bit versions and if you opted for the 64-bit, you may have noticed that there are two Program Files folders on your hard drive. Read on to explore the difference between 32 and 64-bit Windows 7 and why the operating system needs two separate folders in which to store program data.
Windows 7 32 and 64-bit
The real difference between Windows 32 and 64-bit has to do with how much memory the operating system can address. To “address” simply means to “keep track of.”
Windows 7 32-bit (like previous 32-bit versions of Windows) can address up to 4,294,967,296 bytes of information. That’s 4GB of memory. Theoretically, a 64-bit operating system can address up to 1,8446,744,073,709,551,616 bytes of information.
That’s 16.3 billion gigabytes. However, the memory limit on the consumer versions of Windows 7 is 128GB which is still beyond the physical limits of 8GB to 16GB for most motherboards.
Moving from a 32-bit to a 64-bit operating system is more than just a jump in addressable memory. It is a change to a completely different method of keeping track of data. This is why hardware (such as a sound card) needs a completely different driver to work in Windows 7 64-bit.
Two Program Files Folders in Windows 7
If you have the 64-bit version of Windows 7 Home Premium, Professional, or Ultimate edition, you may have noticed that there are two Program Files folders on your hard drive.

One is simply labeled Program Files and the other is labeled Program Files (x86). The first folder is the default location for all of your 64-bit programs. It does not have an extra label at the end because as a 64-bit operating system, it is assumed that you will have only 64-bit applications installed on your computer.
The second folder labeled Program Files (x86) is the default location for all of your 32-bit applications. In a sense, it is a folder designed for legacy software that is left over from the days of 32-bit operating systems. The x86 portion of the folder name refers to the x86 32-bit architecture upon which the first 32-bit processors were developed such as the 386, 486, and Pentium CPUs.
Unfortunately, switching from 32-bit to 64-bit applications and operating systems is not as simple as Microsoft would like. To make the switch, every software vendor, hardware manufacturer, and user would suddenly have to stop making and using anything built on a 32-bit architecture and begin using 64-bit. This is entirely impractical because most people are not willing to just junk their investment in hardware and software and buy everything new again.
Microsoft’s solution to this transition from 32-bit to 64-bit has been to add legacy support for most 32-bit applications. In other words, most 32-bit applications will function in the 64-bit operating environment. Keep in mind that other operating systems operating on a 64-bit architecture cannot load or run 32-bit applications at all.
To help make the transition easier, Microsoft has designated that all 32-bit application should, by default, be loaded into the Program Files (x86) folder rather than getting mixed in with true 64-bit applications in the regular Program Files folder.
Soon, however, most applications will be 64-bit making the need for multiple Program Files folders unnecessary. Still, even Microsoft when it released Windows Vista 64-bit, failed to develop and release a 64-bit version of Office 2007 that was released at the same time.
Keep in mind that by the time we all make the switch to 64-bit applications, it is likely that talk of 128-bit architectures will force us to go through the whole process again.