Problems after re-installing Norton 360

I had a message saying Identity Safe had crashed and I could then no longer access the internet or Norton itself so I uninstalled Norton 360 and then re installed it.

It appeared to be working fine for an hour or two but then strange things started happening like my Hotmail page freezing, being unable to search on Google Chrome homepage, some websites working and others not. 

The symptoms on all of these are the same - the page won't scroll and I can't click on anything.

Don't know what to do next.