Question

What is difference between

Shell(App.Path & "\" & "Hello.exe") 

and

Shell("Hello.exe")

If I put Hello.exe in the program’s folder.

Answer 1

First line will launch Hello.exe from the app folder. If it’s not there, the call will fail.

Second line will try to find Hello.exe in several locations:

1. The directory containing the application EXE.
2. The system32 directory.
3. The system directory.
4. The Windows directory.
5. The current directory.
6. The PATH environment variable.

The call will fail only if Hello.exe is not to be found in any of them.

Related Raymond Chen post: Your debugging code can be a security vulnerability: Loading optional debugging DLLs without a full path.