Vista - IE the only program that can access internet

Hi,

I'm trying to get Vista Home Premium to connect to the net for the first
time. I entered the correct addresses to the properties of IPv4 and left IPv6
on automatic. This resulted in Internet Explorer working, while for example
Opera doesnt (says it can't find a server). Firefox works on the first time I
install it, but once I restart it it gives a blank page. None of the other
software (like my ftp-software) can reach a connection, and even the MS
update software gives a code 80080005 (?) error.
Next I disabled the Windows firewall, but that didnt change anything. I have
no other firewalls/virus protection yet. Windows error correction can't find
anything wrong with the actual connection, so I'm assuming this has to do
with some option I have on in Vista, that I just havent figured out yet...

Anyone got any fresh ideas I could check through?