Browsers not working but internet connection is fine

I'm not seeing a lot of recent talk about this one although I've been hit by it on 4 different computers in our company. Seems like something is going around but can't put my finger on it. No browsers will work on windows 8 or 7. Internet connection is fine. I've tried the cmd resets which seem to work temporarily, however the permanent fix seems to find a restore point and reset the operating system. Has anyone else seen a pattern? Is it a release from MS or viral (sometimes is hard to differentiate...)?

Any thoughts would be appreciated...

George