SysWOW64 on the hard disk, that do not exist on a 32-bit Windows\system32\cmmon32.exe. Maybe you have wondered what these folders are, why they exist and what kind of files they contain? Since the mid-90s almost all computers that have been sold have been 32-bit computers, and mostly they have had a 32-bit Windows installed.

But after the release of Windows 7, the sales of 64-bit computers with a 64-bit Windows installed have increased a lot. Mostly around 3 GB because a large part of the address space is used by video cards and other devices such as network cards, sound cards etc. This is true even if you install 4 GB in the computer. Mostly only around 3 GB RAM will still be used. With 64-bit computers and 64-bit Windows things are different.

Both 32-bit and 64-bit programs can be run on a 64-bit Windows. When a 32-bit program is run on a 64-bit Windows, a 32-bit emulator will be invoked to handle the 32-bit program. There are a few exceptions from this. 64-bit version of the program must be used. As mentioned above the 32-bit emulator handles the situations when 32-bit programs are run on a 64-bit Windows and normally this works fine.

But one sensitive phase is the installation of the 32-bit program. There exists special folders on the hard disk that is intended for 32-bit binary files only and it is very important that the installation program installs the 32-bit binary files to these folders. Data files can usually placed in same folders and shared by both a 32 and 64 bit application. One version is intended for 32-bit files and other version is intended for 64-bit files. Below you can see the full path to the folders. This can be somewhat confusing, but the System32 folder is intended for 64-bit files and the SysWOW64 folder is intended for 32-bit files. This may seem a bit illogical if you look at the folder names, but there is an explanation to this.