How to create a Python application that will run in the background?

I have a task: write an application (on Windows) in python (tkinter, kivy, PyQT, pySide, PyGTK, wxPython, I don’t know what it is, but paying attention to my question you could tell on what to do) that will drag files from one directory to another (these will be .cer .crl certificates). With all this, the program should work in the background (as an antivirus), i.e. I opened the compiled executable, a window came out, I clicked the tab I needed, scored the path from where the files come from and where they are put, then the window closed, but it would work on the background (not minimized, namely on the background) to check after a certain time (let's say every day) if the certificate has expired, and if it has expired, then a message would fly to the desktop (allegedly bro, the expiration date of your mayonnaise can has expired, buy a new one). It looks like an antivirus job, we open it, we hammer in the necessary data, we close it, and as soon as it finds a virus, it makes an alert. I write on the pluses myself and do the web, I don’t particularly hack on python, but I’m grateful for the help to write a task on it.