Weird Internet problems! please help.

[justin_credible]

I'm having weird internet problems. I can get on most sites, but we cannot get on hotmail, ebay or my girlfriends colleges website, and others such as my bank's website. I've tried with Firefox and IE, with Firefox I get connection timeouts, IE page cannot be displayed. I'm living with my girlfriend and I have my own computer in our room, and I unhooked this computer and tried it and those sites worked fine. However because they have school work and papers on this computer, we need it to work on this computer.

I've tried turning the firewall and virus scanner off I've tried removing the nic and turning it back on. I've unplugged the modem for 30 seconds and the computer and plugged it back in and turned the computer back on and nothing has helped. When I typed in the address it just says connecting to www.whatever.com on the bottom of the page and then times out.

It's been happening all day, and it can't be the internet connection since it works on my computer. Any suggestions?