I am running the new Windows 8.1 and just re-installed Waterfox 27. The browser keeps informing me that it is running slowly. The links send me to nowhere because my profile apparently doesn't show the reset button in Help / troubleshooting. The only profile I can locate indicates it is the default profile. This profile only has an alpha-numeric name that was self generated at some point. I was using Waterfox on a previous Laptop using Win7x64 Ultimate I owned, it has sense died. This new Lenovo unit was installed with Windows 8, I allowed the upgrade to 8.1.Operates with an Intel(R) Core(TM) i5-4200U CPU @ 1600GHz 2.30GHz, 64-bit Operating System, x64-based processor. Waterfox has installed itself in the "C:\Program Files\Waterfox\waterfox.exe" folders. I have done an un-install, a reinstall, of your browser.