help with internet

[happy_face]

I would be grateful if someone could help me with my predicament.
I have recently moved back in with my mum temporarily and she's got a desktop with cable internet. I wanted to connect my laptop to her internet and before going out investing in routers and stuff I tried to unplug the internet cable from her desktop and plugged it in my laptop.
When I went to "connections" I could see that it was connected as it said "High speed and100MB" but it was like my browser didn't recognise it as when I clicked on my browser it just said "page cannot be displayed".
Do I need to set something up on my laptop?

Last summer I upgraded my mum's desktop for her and when we plugged in the internet cable to her new machine, there were no problems so I'm a bit confused.

thanks in advance

[CheekyChops]

Do you need to put her ISP password in to the connection settings?

I've got a desktop and a laptop and when I chaned my Tiscali password on the desktop, I also had to amend the settings on my laptop else I got the same error message as you.