HELP PLEASE - computer help forum

I need help really fast. Please answer my question as soon as possible.

I am having internet problems and virus problems. It's all been going one after the other. I have XP I believe.

OKAY PROBLEM:
Whenever I press "Internet" on the desktop, it tells me "This page cannot be displayed. I've tryed so many websites, but will not work. It keeps going to http://if.searchcentrix.com/searchcat.jsp?p=98567&appid=21&type=dns&id=162826192168266&url=if.searchcentrix.com
but I never got the program "centrix".
Okay so I got here by going to My Computer. I put in google.com in the URL of My computer and I got there. I dont want to be going to My Computer everytime I want to go on the internet.
And also, whenever I use the internet, I will get "This page cannot be displayed" for all the pop-ups that I DO want.
Also, I recently uninstalled Ad-aware because I thought it was doing something wrong to the computer(it slowed down the internet a lot and kept freezing the internet), but then I realized it wasn't. The Freezing became more frequent, and I kept restarting the computer. I realized we got a lot of adware viruses(I first thought it was Ad-Aware and was a virus that got detected by Norton Antivirus). I deleted them all, and I got Ad-Aware back. Now this whole internet thing has happened.

SO, please answer quick, because this is NOT MY COMPUTER. It's my friends so please please help. I will be so happy if you can help me ;D