What is a SysWow64 folder

64-bit Windows does not simply compile everything into 64-bit. Intel and AMD have their own plans for what the 64-bit CPU should look like. AMD's answer is straightforward: The new 64-bit processor should be able to maintain compatibility with 32-bit applications while increasing processing power. Intel would like to take this opportunity to design the next generation of processors more perfectly. As a result, AMD's X86-64 (later known as AMD64) processors and Intel's IA-64 (Itanium) processors are available. Unlike AMD64, Itanium processors do not provide a good support for 32-bit applications. The specific information, the reader should be easy to find on the Internet, also do not say more.

Windows, as an operating system, naturally wants users to run a variety of 32-bit applications when they run a 64-bit operating system, as before. This, on the AMD64 processor, is relatively easy to do. And Itanium, it's almost another thing. (Intel later produced a compatible AMD64 processor, but that was something.) )

Although I said "relatively" easy to do, but also not empty gloves white wolf. When the operating system is running at 64 bits, how can you guarantee that 32-bit applications that already exist think they are still running on a 32-bit system? Microsoft's solution is: Wow64, the full name is 32bit windows on 64bit Windows ( 32-bit Windows on 64-bit Windows).

You can also understand that while the entire system is running in 64-bit mode, if a program is 32-bit, Windows will load a "32-bit Windows" on 64-bit basis. This allows the 32-bit application to assume that it is running on a 32-bit system.

So, you can imagine, this means that 64-bit Windows, not only with the 64-bit operating system due to the systems files, but also with 32-bit system should have system files.

As we all know, the Windows system's primary system files are placed in a folder called System32. To be able to put down both sets of system files at the same time, Windows adds a folder, called SysWow64, on a 64-bit system.

This has a problem, System32 and SysWow64 inside, which put the 64-bit system files, which put the 32-bit system files?

If you remember that Wow64 refers to 32-bit Windows on 64-bit Windows, you can think of a 32-bit system file in SysWow64. But you may also ask, why a clearly called System32 folder is a 64-bit system files, and a clearly called SysWow64 folder is loaded with 32-bit system files? Since it's a 64-bit system, Why can't you have a folder like System64 and System32?

This question is very well asked. The answer is also very simple: people in the lake, involuntarily.

Compatibility

If I ask you, how many chances have you had access to the Itanium processor? I think, for the average person, there should be no. Why is it that AMD64 is so much less known about Itanium processors? or because of a key concept in hardware and software design: compatibility.

It is because of the Itanium processor, has not done to the existing 32-bit system to provide good support, it has been on the edge of the market. It's a good thing that you don't buy a high-definition TV that doesn't look at the analog signal channel.

The compatibility that we talked about earlier is the compatibility of 32-bit applications that are already available on 64-bit Windows. Now consider a different kind of compatibility.

If you write a very bull 32-bit application, now you want to turn it into a 64-bit application to make more use of the new processing power that the 64-bit processor brings. You must think that's not the way to get 64-bit compilers to compile it all over again? You may find that this is not the reality of bone. You suddenly find that in your program, for some reason you have not been thinking about, put System32 this folder, written to death in your program. And 32 of this System32 makes you uneasy. You try to run your program, but you find everything is OK. Why? Because this is another aspect of the compatibility of Windows systems: having an existing 32-bit application, unmodified or modified as little as possible, can be compiled into 64-bit applications and run on 64-bit Windows. In fact, to put System32 such a path, written dead in the procedure, is not a case. So, in order to ensure that these applications can successfully transition to 64-bit, Windows finally decided to put 64-bit system files under the System32 folder. And let the 32-bit system files, moved to the SYSWOW64.

You're going to think, what about the System32 that were written in 32-bit apps after 32 people moved to SYSWOW64? A: Windows will turn to SYSWOW64. Does that make the 64-bit System32 turn to System64? Is it really the same? Is it really the same? It's different.

As a 64-bit Windows operating system, it is of course desirable to maximize the potential of the 64-bit processor to allow applications to run more efficiently. If you are running a 64-bit application, always check whether you need to turn, which will affect the efficiency of program operation. So, you can't make unnecessary turns to 64-bit applications, and if you have to turn, you can only turn to 32-bit applications. Yes, there is no way, in the 64-bit operating system, 32-bit application to make some small sacrifice.

In addition, to ensure that 32-bit applications do not conflict with 64-bit applications, in addition to the System32 folder, the registry needs to provide two sets of 32-bit and 64-bit applications, as well as a 32-bit application to redirect when necessary.

Conclusion

So the SysWow64 folder, which is a 64-bit Windows, is where 32-bit Windows system files are stored.

Postscript

Compatibility is an important thing. Of course, it's also a very interesting thing. If you run "winver" in Windows 7, you will find that Windows 7 turned out to be Windows 6.1. Why not? The thing is, Windows XP is Windows 5.2,windows Vista starts to turn 6.0, as a result, many applications just check the operating system version number of the first one, found not 5, so prompted the user said: "We do not support Windows XP previous System ". This is also a lesson learned from the unsuccessful Windows Vista. Perhaps, the future will never be Windows 7.0 also unknown AH.