I have windows 7, I don't like when millions of applications are run in the background and secretly using my bandwidth. How can I disable internet access for all applications except chrome and the likes?
You need to enable the outgoing firewall and block all applications except those you want.
Go to Control Panel > System and Security > Windows Firewall and click on Advanced Settings. There select Outbound Rules and you could start by blocking everything in the list. Then you'll need to add the specific applications you want as exceptions.
Be warned, you may stop programs that rely on having network access from working.