wireless signal is strong but no internet connection

Open a command prompt and see if you can ping 4.2.2.2 (DNS server). Make sure you do not have IE or Firefox set to use a Proxy Server. Make sure there are no entries except for comments (#) in your Hosts file (c:\windows\system32\drivers\etc)


.... Thinkpads_User

If using a wireless router, try connecting physically (Ethernet) to the router to see if Internet works that way or not. If not, then the wireless router may be working fine but a configuration or other issue may be culpable to the Internet connectivity issue itself...

Thinkpads_User
cannot ping 4.2.2.2
Packets sent = 4, Received = 0, Lost = 4 (100% loss)
not sure how to check for entries in hosts file

<<not sure how to check for entries in hosts file>>

C:\Windows\System32\drivers\etc

Open the hosts file with a program like Notepad.

Yobri
 Plugged (Ethernet) cable in, shows wired icon connection in tray. Still "server not found" shows up on I.E.

Is this a home (consumer grade) router like Linksys, Netgear, D-Link, etc.?

Try doing a hardware reset on your router, then check and see first if wired connection works.

... Thinkpads_User

Four host files found in that path:

hosts
lmhosts.sam
networks
protocol
services

in the networks file, the last word is
loopback   127  (this line does not have the # sign)

in the protocol file,
ip      0     IP     # Internet Protocol
icmp 1    ICMP # Internet control Message
(there are about 20 entries with assigned numbers that does not start with the # sign)

in the services file, there are number of lined entries without the # sign.

all other file entries starts with the # sign

So you only have one hosts file (the others are different filenames).

So in your hosts file, the loopback (uncommented) is certainly blocking your connection. Make sure each entry in hosts has a comment (#).  .... Thinkpads_User

It is a computer lab with ten netbooks. Nine can access the wireless router and have internet connection. This one shows full signal but no internet connection.

I made an error above. Your networks file can have that line.

Let's deal only with the HOSTS file (the others are not hosts files). If all the lines in the HOSTS file are commented, then it is probably OK.

Take a look at this Microsoft Article to reset TCP/IP and see if it helps. Follow it carefully.

... Thinkpads_User

Make user that the internal firewall is turned off.

http://windows.microsoft.com/en-US/windows7/Understanding-Windows-Firewall-settings

thanks it's fixed.

Thank you. I was happy to help. Long post for the little things, but I am happy TCP/IP repair worked.

.... Thinkpads_User