Weird problem viewing web pages in any browser after spyware attack

Hi there, I have a very unusual problem after a spyware attack.
I am on a firewalled windows network at my house. There are 5 computers on the network, but internet access is fine from all the others. There is a Windows 2003 proxy server in front of the router.

On my machine I had a spyware attack which damaged windows so the start bar didn't appear. I repaired the windows installation, and most problems were fixed.

I now have a strange problem where in any web browser (IE, Firefox, Opera) no web pages load either by using DNS or IP address.

In the command prompt NSlookups work, as does ping etc.

I can't seem to use FTP in any web browser either.

However when another program calls up a browser window such as RSSReader the websites load fine, but when called up from a proper browser window with address bar and menus etc. it refuses to load the site. So it seems to be the way which any web browser is calling on windows and using HTTP.

Any ideas on how to fix this? Have downloaded all the latest updates etc. It's not browser specific but a problem with the routines that handle web traffic in Windows.

 

thank you very very much this problem has been plaguing me for ages. What causes SP2 to do that? Why does the DNS cache get confused in that way? What does the nsh command do then?