Internet Explorer -connection won’t work

This is lengthy:
There are 2 computers on our network that cannot connect to the internet. These are 2 out of 8. All 8 are setup exactly the same. All 8 can access our network and all have LAN internet access. Six of the computers are connecting to the internet fine. These 2 are not. The message “can’t diplay page” appears everytime. The connections are good and everything appears in order. I cannot find any difference in the way that these 2 are set up and the others. These 2 can access the network so I don’t understand why the internet connection doesn’t work.
Any help you can give me would be very appreciated. I have tried everything and then some.