The application was unable to start correctly (0xc000007b)

I have a client/server app which I have been developing on a single PC. Now it needs two serial ports, so I borrowed a PC from a friend.

When I build my app and try to run or debug it (whether in the Delphi IDE or from Windows File manager), it errors "The application was unable to start correctly (0xc000007b)".

Googling doesn't bring up much, but seems to indicate that this is nothing Delphi specific and happens with other apps. It seems to be caused by calling into a 32 bit DLL from a 64 bit app or vice versa.

  • both PCs are Windows 7, 64 bit
  • both have Delphi Xe2 starter edition which can only handle 32 bits
  • The app runs fine on my PC, but not on my friend's
  • Other Delphi apps run just fine on both PCs

Can anyone give me a hint as to how to track this down?


To start, I would suggest to test whether there is a problem between your application and its dependencies using dependency walker


A load time dependency could not be resolved. The easiest way to debug this is to use Dependency Walker. Use the Profile option to get diagnostics output of the load process. This will identify the point of failure and should guide you to a solution.

The most common cause of this error is trying to load a 64 bit DLL into a 32 bit process, or vice versa.