Want to create an invisible bot to crawl website

I want to create a bot that crawls a certain website at every X amount of days and this needs to be running in the background hidden from the user. Sort of like a spyware.

Does anyone have any ideas on how to go about this? I'm still new to .Net programming so I'm not sure if this project is a windows application or a console application or a windows service??

I need to know how to make an application invisible so it runs in the background, it also needs to know how to start up when windows is restarted. Stuff like that.

If someone can point me to the right direction or give me guidance on how to build this thing, that'll be awesome.