How to make a automatic thing?

Question

How to make a file that runs automatic and do things on background? , like viruses or like those apss that run at startup of Windows

Answer 1

Well, for Windows, a key in the Registry should be included in order for a program to run at startup. Up until Windows 7, I also confirmed placing a program under the "Startup" folder does more or less the same thing. This article deals with the latter issue: https://www.howtogeek.com/208224/how-to-add-programs-files-and-folders-to-system-startup-in-windows-8.1/

On the other hand, such programs are specially codified in a way they have no visible UI, embed inside the notification bar, and respond to various types of events. An example using C is found here: http://nova.pc.pl/modtsr.pdf

Even for programs not designed to embed into the notification bar, other programs exist that take care of them. One of them is in the following link: https://superuser.com/questions/132661/how-to-put-a-program-in-system-tray