Network issues.

[GroundWalker]

I'm currently writing from my laptop connected to the same router as my desktop.
For some reason, I can't access websites from my desktop, though I can use pretty much anything else. (Dropbox, Steam, Messenger etc.)
This has been going on for a few days, and I've tried many different things.
I know one thing; it isn't a DNS problem...at least none which I'm aware of. (I've tried connecting with IP adress to several sites, and it still won't work.

Not sure what information might be important for this, but I can provide most information if need be.

Would be very thankful for any help to get this solved, since it's getting quite annoying.
Thanks in advance.

 

[evilneko]

Does this happen in all browsers? Do ping and traceroute work? What sort of security apps are running?

 

[GroundWalker]

Sorry about the 'somewhat' late reply.

All browsers, ping works, both between computers and to websites.
Traceroute?
I'm running the built-in Firewall of Windows XP and ESET NOD32 AntiVirus.
Forgot to mention, that even though I can log in to Steam and such, I can't browse the store.

 

[GroundWalker]

If it's of any relevance, the computer doesn't show up in the routers DHCP-list.
Not the IP, not the computer name.

 

[evilneko]

Is the computer even set to use DHCP?

Compare the output of ipconfig /all on your laptop and desktop. Some things will naturally be different such as MAC address and adapter name of course.

Compare the actual TCP/IP settings under network connections as well.

Seems like anything that uses the HTTP protocol is failing though, or outbound to port 80 is being blocked by something. Windows firewall does not block outbound at all though. That's NOD32 Antivirus, not NOD32 SmartSecurity, right? Anyway, just for fun try connecting an SSL-only site like https://www.paypal.com/ since SSL goes to a different destination port.