I just happened to realise that the WinExec API does not function under
Windows 7 (haven't tried under Vista yet, but will do soon) when the application has a manifest requestedExecutionLevel asInvoker.
with requireAdministrator however it works ofcourse.

Is there a way around this?

As a replacement I'm currently using the ShellExecute API to execute .exe's, but the problem with this API is that it requests command line arguments separately, so I have to personally code & detect and pass them on, where as on the WinExec API it does it for you.

Any solutions?