Norton Family greatly slowing down browsing

Hello

 

We have had a problem with Norton family slowing down our browsing considerably for the last few months. Our system operates Windows 7 64bit. The problem occurs on both firefox and explorer, both of which are up to date. I have uninstalled and reinstalled NF several times, but each time the problem persists. When I first startup the problem isn't too bad, but it gets progressively worse and then often results in the browser crashing.

 

When NF is uninstalled browsing is fast and problem free. We do like the features that NF offers us and so it is very frustrating not to be able to use it.

 

Any advice would be greatly appreciated.