Given that this was happening in two browsers it was always something of a long shot. That leaves a choice between your internet connection and an OS problem. If you could get a friend to come round with their laptop or a tablet and try connecting to your internet this would be helpful. If their laptop suddenly has the same problem then it is an internet problem, either your router or your connection. Of course if they have no problems then it is your computer !
Also it would be very easy to run the System File Checker on your computer, this fixes, or tries to fix, faulty or damaged Windows files. Since you are runninng Win 7 click 'Start - All programs - Accessories'. There you will see 'Command prompt', RIGHT click on this and choose 'Open as Administrator'. A black window with white text will appear with a blinking underscore, this is the insertion point. Type 'SFC /SCANNOW' then press enter. Do not include the ' ', note there is a space between SFC and /SCANNOW and it is not case sensitive. It will start to run when you press enter and can take quite a while, an hour is not unusual but do not interrupt it until it has finished. When it has finished it will produce a report on screen which will say one of three things (in translation)
(1) No problems found
(2) Problems found and fixed
(3) Problems found and NOT fixed
There is also the possibility it may not complete. Post back and let us know how you get on.