I recently upgraded my OS from Windows 7 Ultimate 32-bit to 64-bit. I have never had any problems with the 32-bit version, but I needed a new HDD and so with the new HDD got the 64-bit version of the OS.
For some reason, browsers (all of them) seem to stop working quite consistently. After using the browser (any one, I've tried, Firefox, Waterfox, Chrome, IE) for a while (anywhere from 1 hour to a couple of days, the browser would suddenly stop working. It doesn't exactly crash, but it keeps spinning like it is trying to connect to the internet but can't, even though I've pinged the internet from the command line and am able to connect and get a reply.
I thought it was a network problem, so switched network cables and ports on my router, that did not help.
I thought it was a 64-bit issue, so I went to Waterfox, which is the 64-bit version of Firefox, that does not help, still experiencing the same problem.
The only thing that fixes it, is if I reboot my computer.