windows 8 nework connectivity

When I do a troubleshoot for connection I get trouble with network connectivity and internet connection, Dell could not find the answer and neither could Microsoft but they found problems with connection address .what my problems when I go on a web site and try to get something off the web site the internet will say the address is correct but cannot connect

How are you connected to the internet? Wired? or wireless?

I have wired when I do a network diagnostic both the network and the internet connection have problems. Microsoft worked on the computer and only said he fixed problems with connection with internet provider. but when I do the troubleshooting both connection have problems when I get on a web site. the internet will say the address is right but cannot connect, both dell and Microsoft. If there is anything else you want to know just let me know. thank you