Chrome and Firefox not loading

I have a PC I'm trying to help someone with where both Chrome and Firefox open, but pages won't load. Chrome doesn't load anything at all (pages, settings, bookmarks etc), whilst in Firefox I can access settings etc, but pages won't load (just sits on the loading symbol). Other browsers on the PC work fine.

I've tried:

Un-installing and re-installing both browsers
Running Malware Bytes, Junkware Removal, ADW Cleaner, CCleaner

Funny thing is, they are both fine in Safe mode - I removed a couple of extensions from Chrome in safe mode (two Norton extensions and some janky "Mapsgalaxy" one), and also noted the "start Chrome on a specific page" setting was linking to some random search page, so I fixed that too. Then logged back in normally, still no luck.

Could it be that even after uninstalling the browser, there's still some stuff hanging around in the app data folder, that I need to remove?

Any help would be very much appreciated!
 
Solution
See if same thing happens on a clean boot - if it doesn't, its one of your start up programs, have a look at firewall or AV. Slowly re add start up programs to find the cause

Have you tried setting up a new local account and see if it happens to them as well? Make them admin or the password prompts may drive you mad