Port 80 goes dead out of nowhere

Hi,

I have a very bizarre problem.

I'm on Windows 7 - 64.
Router - DLink 6740U
Network - 2 Sat receivers, HTPC, Desktop, Laptop. All but the last wired. Laptop on wireless.

Lately, once in a day, I'm unable to browse the internet. Skype, IRC and all the other traffic still go, but for no reason at some point I can't surf anymore. I get a 105 error on Chrome (Error 105 (net::ERR_NAME_NOT_RESOLVED), and...well other browsers as well and that's it.

The only chance to have the ability to surf again is by restarting the router.

- The desktop is working fine. No changes.
- Once the browsing is dead on the laptop I tried using a cable, but that didn't help as well.

I used telnet once the browsing switched off and indeed port 80 wasn't functioning.

I tried to disable the firewall of Win 7, of the router and my AV (NOD32) but... it didn't make any change. Actually only made things worse and the drops were in much higher frequency.

Spoke with my ISP and after hours of attempts (including resetting all the network, winsock and W7 firewall) gave up and said it's some sort of a virus on my laptop.

Nod32 didn't find any. Malwarebytes didn't find any.

Before I format and hope for the best... any idea if I'm missing something here?

Why would port 80 stop to work all of a sudden for no reason on a specific station?

Thanks in advance,

Alright. Done. There were tons of links there.

Care to explain what is this supposed to do...?

Just trying to figure out these things so I won't have to bother you guys in the future in case things happen again.

Alright. Let's wait and see...

Thanks!

Back to square one.

Took 18 hours and it came back again.

What else can be done?