Timer vs. Sleep? Did I say that? I didn't say that.
Timer vs. Loop
Anyways, Timer vs. Loop or Timer vs. Sleep, Better?
Guess it depends on what is being done. I just gave some options.
Not much more help can be given with-out knowing if the called programm is a Visible task or not (because of effects using Sleep or WaitForSingleObject, meaning a need to use a minimal timeout, add a doevents, and locking the calling application), and if in the calling has some other task already running which also needs to be suspended.
Just assuming that the called programm is an application, in which it is desired that the calling application should simply be suspended or locked until the called programm is closed (Simply: a user wants to start see a picture, clicks on a button and for this a picture viewer is started, suspending the calling applicaiton) and no tasks in the calling application are running (this being called inside of another proceedure and waiting on a result).
But, cspm2003 asked the question, so it more help is needed then they can further question.