cant access some sites with new laptop

I have just bought a new laptop for my daughter and we are having some difficulty accessing some websites.The laptop is new and is using windows vista. I also installed a new wireless router but this is working fine on the desktop. Most websites are fine but i cant get on to paddy power poker and my daughter is having the same trouble with a kids sites called club penguin and star doll. We cant get on to you tube either. I would be very grateful if anyone can help but please be gentle with me as I am a complete technophobe.