C# System.Diagnostics.Process: can't launch a 32 bit exe file in 64 bit OS

Question

I have a 32 bit exe file compiled with Turbo Pascal. I need to launch it. It worked well when I had Windows 7 32 bit, but now I'm on Windows 7 64 bit, and I get the following exception:

The specified executable is not a valid application for this OS platform.

To make sure it works on 32 bit systems, I launched the C# program in a 32 bit platform - it works.

So how can I launch a 32 bit exe file in 64 bit OS?

Thanks

Answer 1

Turbo Pascal could only generate 16-bit code, there was never a version that could create 32-bit executables. Running 16-bit code requires a virtual machine that uses the real-mode emulation support in the CPU (virtual 8086 mode). This emulation is not available if the processor is running in 64-bit mode.

You cannot run 16-bit processes on a 64-bit operating system. You may have a shot at getting it going with the DOSBox emulator.

Answer 2

If you're launching the 32 bit exe from within a .NET (C#) application, then you'll need to set the target for your .NET app to x86. If it's set as Any CPU, then it will run as a 64 bit process on a 64 bit OS and therefore won't be able to launch the 32 bit process.

Edit: This MSDN article explains how to modify this setting: http://msdn.microsoft.com/en-us/library/5b4eyb0k.aspx

Edit 2: As Gabe points out, there shouldn't be a reason why the 64 bit app could not start a 32 bit exe. I know you can't use a 32-bit DLL from within a 64-bit app. Just thought it would be worth trying since the documentation doesn't specify if that same restriction exists when using System.Diagnostics.Process to launch an exe.

Answer 3

You can launch 32bit application from 64bit application.

C# Example 1:

var processStartInfo = new ProcessStartInfo("C:\MyApp.exe");
var process = new Process { StartInfo = processStartInfo };
process.Start();
process.WaitForExit();

C# Example 2:

System.Diagnostics.Process.Start("C:\MyApp.exe");

Answer 4

I don't think there is a 64 bit compiler for Turbo Pascal so I think your only choice is to compile your app targeting a 32 bit enviornment.