Running 32-bit Applications
WOW64 is the x86 emulator that allows 32-bit Windows-based applications to run seamlessly on 64-bit Windows. WOW64 is provided with the operating system and does not have to be explicitly enabled. For more information, see WOW64 Implementation Details.
The system isolates 32-bit applications from 64-bit applications, which includes preventing file and registry collisions. Console, GUI, and service applications are supported. The system provides interoperability across the 32/64 boundary for scenarios such as cut and paste and COM. However, 32-bit processes cannot load 64-bit DLLs for execution, and 64-bit processes cannot load 32-bit DLLs for execution. This restriction does not apply to DLLs loaded as data files or image resource files; for more information, see LoadLibraryEx.
A 32-bit application can detect whether it is running under WOW64 by calling the IsWow64Process function. The application can obtain additional information about the processor by using the GetNativeSystemInfo function.
Note that 64-bit Windows does not support running 16-bit Windows-based applications. The primary reason is that handles have 32 significant bits on 64-bit Windows. Therefore, handles cannot be truncated and passed to 16-bit applications without loss of data. Attempts to launch 16-bit applications fail with the following error: ERROR_BAD_EXE_FORMAT.
In this Section
- Performance and Memory Consumption Under WOW64
- WOW64 Implementation Details
- Registry Redirector
- File System Redirector
- Memory Management
- Processor Affinity
- Interprocess Communication
- Application Installation
- Debugging WOW64
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Build date: 1/27/2011
- 3/30/2012
- Kranthi Kumar V
- 5/22/2012
- kit1800
This page is for developers, programming information for how to deal with some interesting issues that 32 bit applications running on a 64 bit operating system may have to deal with.
Anyway, by default, a 32 bit application runs on a 64 bit version of Windows just by double clicking on the executable or what other method you choose. I bet you that if you look at the processes list in task manager on your system, you will see applications with *32 next to them in the image name column, this is a 32 bit process.
It could be that the problem you are having isn't with a 32 bit application, but with a 16 bit application, or with some instances of Windows Server 2008, you can actually install it so that it doesn't have WoW64 support.
So I would suggest trying the following. First, make sure you can run other 32 bit executables on your system (your web browser is probably the best option since as of Windows 7, the 32 bit version of IE is default, firefox is still 32 bit only afaik and others are too). Check task manager for any processes with a *32 next to them and if one of these works then your system is capable of running 32 bit applications.
Finally, if you are having problems, give the error that is occuring. Do you know how likely it is that the problems that are occuring is being caused by the application just malfunctioning under WoW64? If you want support aimed at users, not developers, go to http://answers.microsoft.com and ask there.
- 4/29/2012
- crescens2k
- 2/27/2012
- rattleduser
- 2/24/2012
- Jarnoldus
- 12/21/2011
- dar501
- 12/21/2011
- dar501
