Cannot Find Server/ Page cannot be Displayed......Please Help

After a while a gettin real p!$$3d off with my sisters laptop i sent it back to the manufacturer to be fixed....they sent me it back all shiny and good....however now when i want to go onto the internet it wont work...

I got it home pluged it into the network and it was working fine, so i turned it off and moved it into my sisters room. I plugged it into the network there and all that came up was the stupid 'page cannot be displayed' page. So i figured that i would try what i said to Do....nuthin happens.

So i Though that since it worked in my room earlier id try it back in there...still no joy!

Things ive tried:

Playing With Proxy servers ( but the other computers dont use em)
Reinstalling Internet Explorer
Reconnecting the server (im on ADSL by the way)


Also i thought that the network wire might not be working so i tryed tranfering some files across from one compuyer to another...it worked fine. I can also connect to msn messenger on the laptop and winmx etc. but i cant browse the internet.

I CAN brwse the internet on other computers on the network so it cant be a problem with the router


Any Suggestions?
Thanks for your time
Ben

It sounds as if it could be a DNS problem. If possible I would suggest contacting your ISP and getting their DNS servers and inputting them into your local computer Network Connection Properties. You can also go to Start >> Run, then type in command. Once there type "ipconfig /flushdns" without the "" marks.

My ISP's customer support is 100% useless. They dont know what they are talking about. I tryed the ipconfig/flushdns thing. But same old page 'page cannot be displayed' screen.

It has something to do with dns. On the status bar at the bottom when the page loads it says 'dnserror'

any more suggestions?

thanks for your help