How do I find out what programs are running when I start up my pc and ...?

click on start then run' type in msconfig and go to the startup tab. Usually you can unpick everything except the firewall or internet suite you might be using. If it's the internet that is slow and not the pc itself you might have to update or reinstall the ethernet driver or reinstall the browser or even the isp software. Those are going to be the easiest things to try first. Don't mess with the services unless you know exactly what each one does and which ones really need to be on.