Can connect to router but not internet.

My dell xps17 used to work fine, it connected to the Internet within seconds of startup. We also have another dell laptop which has always worked fine too. However yesterday my laptop stopped receiving Internet connection. The other dell laptop and the iPad still connected fine. It can still connect to the router but no websites work. I did a Mcaffee virus scan and it found and removed a trojan, we googled it's name (on the iPad) and checked that mcafee had removed it completely. It did. I still cant connect to the internet on my laptop, but the router can still be connected to. I bought my laptop on the last week of April this year, It has: Windows 7 64bit Intel i5 6gb ram 555m 3gb graphics card About 700gb hard drive The other dell laptop also has mcafee, and many places on the Internet have suggested removing it. This seems like a bad idea because if it works I will have no protection against nasty viruses. Also when I got the laptop I paid for extended mcafee protection time, and it would be a shame to waste the 970 days that I've got left. Please help!