Debugging a program that doesn't start

Question

How would I go about determining why a VB6 (or 5) application doesn't start? I can't attach a debugger to it because of that. I have IDA Pro Freeware at my disposal, but need some pointers as to where to start with it.

I don't have the source for this program, only the .exe. When I say it doesn't start, I double-click the .exe, and nothing happens - there is no process left running - nadda.

Running under admin it creates three empty folders, then exits silently before a UI is shown. OllyDbg tells me there was an 'Inexact floating point result', but I need to spend a few hours or days learning to interpret all the info OllyDbg gives me. My book on Advanced Windows Debugging should arrive on Monday or Tuesday as well.

Answer 1

Are you saying the program starts but crashes before you can attach? If so try launching the program under the debugger.

In Visual Studio you can do this by going to

• File -> Open Project
• Select the EXE in question
• Hit F5

Answer 2

It seems like I answer with this a lot, but try looking at the Windows Events log. There is often information here that can be useful, such as a control, or dll your program depends on that was not found.