'Lag' occurs when first loading a website though reported ping is fine

Ever since I reinstalled Windows 7 Pro on my desktop, new websites (or websites I've left alone for a 'while') are slow to visit on my UK broadband connection.

I'm sure there are dozens of potential sources for the problem, but I'll try and be as specific as possible. I'm techy (since I program for a living), but know next to nothing about networks or troubleshooting internet/network problems.

Here we go. The problem is with my desktop's internet connection, though my laptop (which is also connected to the same wireless home network) has no problem, so I don't think the problem is with my ISP or Belkin ADSL2 Wireless-G router/modem.

I thought the problem was the 'ping', but speedtest.net reports 30ms ping and 2mbps download, which is about the same as my laptop. I also tried Firefox as well as Chrome, but the problem occurs there too.

Even Google will take around 10-20 seconds to load on a 'first' visit. The screen is blank meanwhile, and the mouse cursor changes to the 'waiting' mode.

I tried "Troubleshoot problems" in Windows' "Network and Sharing Center", but Windows didn't find any problem.

How can I go about fixing this?

Okay, this thread can go into 'suspend' at least for a bit. I also tried to unplug/replug the router, and (shock), reboot the PC, and it's much better, more like 1-4 seconds. Perhaps there's a way to cut this down even further (?), though I guess certain sites and/or locations have a natural lag to them anyway due to distance or server quality etc.


Anyway, I'll update if the problem reoccurs.