Connection closed by Server

Maybe you guys know whats up

On one Windows 7 PC, I get the connection closed by server, with EVERY browser on every page
refreshing once or twice and it works

I flushed the DNS, but other than that I have no idea - no proxy settings and a dnslookup tool didnt show any problems either D:

And it works fine on other computers? are these other computers the same OS? Have you tried pinging webpages, if so what happens?

and finally, http://www.youtube.com/watch?v=p85xwZ_OLX0

Im on a laptop now… its all perfectly fine now… windows XP on Laptop, windows 7 on PC

pinging seems to work fine and fast on the problem pc

I restarted everything since I disconnected everything from power last night, even router and stuff

try running and AV scan, cause sometimes you can get strange viruses, like one time I had one that would only let me go to google youtube facebook and yahoo.