internet connection turn off ever 10 minutes for 30 seconds

i have wireless as well as wired connection. in both of them my internet connection does not work after working for 10 minutes. In mozilla it says server not found in internet explorer it says diagnose internet connection.... problem persist for 30 seconds
whereas my networking is working fine no problem in that, I am facing problem only in Internet Connection
i do not know what to do . i have formatted my computer but problem is not resolve
have gone through in-numerous blogs thread you name it.