虽然Windows XP确实有 64 位版本，但直到微软(Microsoft)发布Windows Vista之后，消费者才真正决定购买 32 位还是 64 位版本。
Windows 7/8/10 还提供 32 位和 64 位版本，如果您选择 64 位，您可能已经注意到硬盘上有两个Program Files 文件夹。(Program)继续阅读以探索 32 位和 64 位Windows之间的区别，以及为什么操作系统需要两个单独的文件夹来存储程序数据。
Windows 32 和 64 位
Windows 32和 64 位之间的真正区别在于操作系统可以处理多少内存。“寻址”只是意味着“跟踪”。
Windows 7/8/10 32 位（与以前的 32 位版本的Windows一样）最多可以寻址 4,294,967,296 字节的信息。那是4GB的内存。理论上，64 位操作系统最多可以处理 1,8446,744,073,709,551,616 字节的信息。
那是 163 亿千兆字节。但是， Windows 7(Windows 7)消费者版本的内存限制为 192 GB，这仍然超出了大多数主板的 8GB 到 16GB 的物理限制。对于Windows 8来说，它是 512GB，而对于Windows 10来说，它是高达 2 TB 的内存限制！
从 32 位操作系统迁移到 64 位操作系统不仅仅是可寻址内存的跳跃。这是对一种完全不同的数据跟踪方法的改变。这就是为什么硬件（例如声卡）需要完全不同的驱动程序才能在 64 位Windows中工作。
Windows中的两个程序(Program)文件文件夹(Folders)
如果您有 64 位版本的Windows ，您可能已经注意到硬盘上有两个Program Files 文件夹。(Program)
一个简单地标记为Program Files，另一个标记为Program Files (x86)。第一个文件夹是所有 64 位程序的默认位置。它的末尾没有额外的标签，因为作为 64 位操作系统，假设 64 位应用程序将进入此文件夹。
标有Program Files ( x86 ) 的第二个文件夹是所有 32 位应用程序的默认位置。从某种意义上说，它是为 32 位操作系统时代遗留下来的遗留软件设计的文件夹。文件夹名称的x86部分指的是x86 32 位体系结构，第一个 32 位处理器是在该体系结构上开发的，例如 386、486 和Pentium CPU(Pentium CPUs)。
不幸的是，从 32 位切换到 64 位应用程序和操作系统并不像微软(Microsoft)想要的那么简单。为了进行转换，每个软件供应商、硬件制造商和用户都将突然不得不停止制造和使用基于 32 位架构的任何东西，而开始使用 64 位。这是完全不切实际的，因为大多数人不愿意放弃他们在硬件和软件上的投资并重新购买所有新产品。
Microsoft 针对从 32 位到 64 位的过渡的解决方案是为大多数 32 位应用程序添加旧版支持。换句话说，大多数 32 位应用程序将在 64 位操作环境中运行。
为了帮助简化转换，Microsoft已指定默认情况下所有 32 位应用程序都应加载到Program Files ( x86 ) 文件夹中，而不是与常规(x86)Program Files 文件(Program Files)夹中的真正 64 位应用程序混合。
Windows使用各种模拟器在 64 位Windows中运行 32 位应用程序。您可能已经在系统上看到了一些带有WOW64一词的文件夹。WOW64代表Windows 64(Windows)位(Windows 32-bit)上的 Windows 32位。每当您运行 32 位程序并且它需要访问程序文件目录时，它都会使用WOW64无缝重定向到 C:Program Files (x86) 。
您只需浏览两个文件夹即可快速查看计算机上的哪些程序是 32 位的，哪些是 64 位的。
每隔几个月，我通常会查看软件开发商的网站，看看他们是否发布了 64 位版本的程序。有时您必须深入挖掘才能找到 64 位版本的程序。即使在今天，大多数供应商仍将 32 位版本作为主要下载。例如，您可以安装 64 位版本的 Office 365(install the 64-bit version of Office 365)，但它不是默认下载。
然而，很快，大多数应用程序将是 64 位的，因此不需要多个Program Files 文件(Program Files)夹。尽管如此，即使是微软(Microsoft)在发布64 位Windows Vista时，也未能开发和发布同时发布的 64 位版本的Office 2007。此外， Windows 10(Windows 10)中许多来自Microsoft的默认Windows Store应用程序仍然是 32 位应用程序。
请记住，当我们都切换到 64 位应用程序时，谈论 128 位架构可能会迫使我们再次经历整个过程。享受！
Why Does 64-bit Windows Need Two Program Files Folders?
Although Windows XP did have a 64-bit version, it wаsn’t until Microsoft released Wіndows Vista that consumers really had to make a dеcіsion of whеther to buy the 32 or 64-bit version.
Windows 7/8/10 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 and why the operating system needs two separate folders in which to store program data.
Windows 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 7/8/10 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 192 GB which is still beyond the physical limits of 8GB to 16GB for most motherboards. For Windows 8, it’s 512GB and for Windows 10, it’s a whopping 2 TB for the memory limit!
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 64-bit Windows.
Two Program Files Folders in Windows
If you have the 64-bit version of Windows, 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 the 64-bit applications will go into this folder.
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.
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.
Windows uses an emulator of sorts to run 32-bit applications in 64-bit Windows. You may have seen some folders on your system that have the term WOW64. WOW64 stands for Windows 32-bit on Windows 64-bit. Whenever you run a 32-bit program and it needs to access the program files directory, it is seamlessly redirected to C:\Program Files (x86)\ using WOW64.
You can quickly see which programs on your computer are 32-bit and which are 64-bit by simply browsing into the two folders.
Every couple of months, I normally check the software developer’s website to see if they have released a 64-bit version of the program. Sometimes you have to dig a little to find the 64-bit version of a program. Most vendors even today still push the 32-bit versions as the main download. For example, you can install the 64-bit version of Office 365, but it’s not the default download.
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. Also, a lot of the default Windows Store apps from Microsoft in Windows 10 are still 32-bit apps.
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. Enjoy!
