How to Fix Program.exe is not a valid Win32 Application Error?
File is corrupt, bad, or missing
If the file or program you're attempting to run is corrupt or missing, Windows will be unable to execute the file properly and sometimes generate this error message.
Download files
If you downloaded this file and verified it is complete and compatible with your version of Windows, delete the file and try downloading and running it again. It's possible during the download that the file became corrupted.
Finally, if the second download does not work, try downloading the file from a different webpage. It is possible that the person or company maintaining the website mistakenly uploaded a corrupt version of the file you're attempting download.
Installing a program from a CD or other disk
If you're attempting to install a program and are getting this error, verify that the CD is clean. If the CD is dirty or bad, you could get this error during the install or after the program has been installed because it was not copied properly onto the computer.
Running a program from the computer
If you're running the program from a shortcut on the computer, verify that the program is still on the computer. In some cases if the program is no longer installed on the computer you may get this error.
If the hard disk drive is corrupted or bad it can also cause working programs to fail either because not all the data can be read from the hard disk drive or because the program has become corrupted while on the drive. Run scandisk and defrag on the hard disk drive to check for any potential errors.
Long file name issue
Make sure the program or file you're attempting to run does not contain the same name as the long file name directory it is contained in. For example, executing a file named "program" in the "program files" directory can cause errors in some versions of Windows.
Additionally, if you're attempting to install a program and after the install the program does not work, you may also want to try installing the program in a different directory.
Bad file
Any file can be changed or renamed to be a .exe file. If you're downloading the file, make sure the file is supposed to be a .exe file and that it's not being changed. If you're attempting to create a .exe, file make sure you're compiling the file for Windows and never just rename a file to a .exe file. For example, renaming a .bat file to a .exe file will not make the file an executable file. For a file to become an executable file it needs to either be compiled or converted through a software program designed to convert the file.
File is not designed for your version of Windows
If you're trying to run a program that is not designed for your version of Windows you may get this error. Although many older programs designed to work in older versions of Windows will work with new versions of Windows, unfortunately, not all programs will work.
   If the program is an older MS-DOS program or early Windows program you may get this error.
   If the program is designed for a 64-bit version of Windows and you're running it in a 32-bit version of Windows, it will not work and generate this error.
Getting old MS-DOS games to run in Windows.
File is a virus, worm, or other malware file
This error can be generated by a file that is a virus, worm, Trojan, or other malware file. Often, this will be caused because the virus scanner installed in the computer will not allow the file to be installed or run. Try scanning the file to verify it is not a virus or infected.
If the file has been checked and is clean, it is still possible that the virus protection program or another program installed on the computer is causing issues during the install or execution of the program. Boot the computer into Safe Mode and try running the program; booting the computer into Safe Mode will make sure nothing is running in the background that could be causing this issue.
Hardware incompatibility
If you're getting this error during the installation of a program it's also possible that the CD-ROM drive or the drive you're installing the program from is not compatible with Windows or has drivers that are not compatible with Windows.