Internet connection problems... help!

Alright, I left my computer on last night, and I went out. My dad checked his email after I left and had shut it down. This morning I go on it, to find that the internet does not work at all on it. I can't ping any websites, I checked the cables and they're all fine, and in IE when I open it, it takes up a LOT of CPU memory and says at first finding www.yahoo.com which is my homepage, and switches to "Finding site badurl.grandstreeinteractive.com" System restore was turned off for God knows what reason, so now I have no restore points, and I have no clue what to do... can anyone help?

Windows XP Home Edition SP1
512 MB RAM
80 GB HD
P4 1.7 GHz
Comcast Broadband
IE 6
Mozilla (doesn't work either, nor do AIM, MSN, ICQ, or anything that connects to the internet)

EDIT: The URL is badurl.grandstreetinteractive.com but I still don't know if that has anything to do with it... I also get an error when I try to renew my IP address: "An operation could not be performed on something that is not a socket" or something along those lines.

You said you father had checked email...is there any possibility of a virus in an attachment? It seems to be a virus, and if it really is, do not try XP restore, it can be worse.

Restore was off, and he checked his work email, trust me there weren't any viruses in there. Nothing without the @********.com domain gets through. And I just don't want to supply the company name, it's not relevant.

that doesn't mean anything JKozzy, viruses don't necessarily spread from such addresses but most of the time they come via friends

anyway, do a virusscan and a spyware-scan and see what it comes up with

Format your working partition and reinstall XP (or try and use the recovery option)

Do you have a virus scanner / spyware dectector?

If not, go to another (friends) computer and download it and put it on a CD.

AVG: http://www.grisoft.com/us/us_dwnl_free.php
Spybot: http://security.kolla.de/

u should be aware that some viruses/spyware uses u'r computer to ping remote hosts.. and most ISP's consider this flooding and will block all trafic to and from u'r PC until the problem is solved... do u have a firewall installed ?

it could be hacker 😑

Kozzy you checked your traffic, I once had a damn Virus that caused massive Upload (as big as my entire connection width and then it was like I couldn't get on-line)

(LONG LIVE FIREWALLS)