If we need to write a program that works periodically, which way do we prefer? Writing a windows service or writing a console application which works as scheduled task?
Avoid a service unless you must use it.
It is a process - which means it runs all the time. Gratitious use of system resources is bad practise.
I personally find it insulting that other people have their process executing 24/7 on MY computer when it is entirely unnecessary. It's MY performance they're using up. I disable all non-necessary background services.