Somehow Store got corrupted and it took a long time to get it back as various fixes (WSReset, Powershell commands) did not work, because (as I discovered) I needed to activate Windows Firewall. Then I found no apps would download --- it was the Firewall again. Now the Store and apps are working but I have lost Cortana and Search. Clicking on them has no effect. How do I get them back?

Also, which may or may not be connected, links to webpages have stopped working. For example, if I have a link in an advert or a notification in an email, clicking on it produces a 'we cannot open' notification. If I copy and past the url directly in a browser that does work.