All the browsers I've tried - Chrome, Firefox, IE 10 - seem to run slowly/crash after a few days. Deleting history doesn't help. Deleting Chrome or Firefox completely and reinstalling seems to get them working again for a day or so then problems begin. It's a problem even if the only thing I run is the browser and it seems to affect other programs as well.
I've tried disabling add-ons which seems to make things worse! Private mode is just as bad.
I wonder if it's a Flash issue as after installing it things seem to go wrong - and I do want it for certain sites. But maybe that's coincidence?
Any advice welcome.