Latency issues in Team Fortress 2, but only after joining a game

I've just tried to play Team Fortress 2 for the first time for quite a while, and I am afraid I am plagued with a very annoying issue.

When browsing for servers, I consistently see very good pings on the servers I previously used (~30ms). However, once I join an actual game I suddenly find myself with a ~800ms ping and everything becomes completely unplayable.

Searching the web, I suspected it might be the Multimedia Class Scheduler Service, so I turned it off. Sadly, that was no help at all, so I also tried this suggestion (to turn off TCP Auto-Tuning) to no avail.

I was once able to play TF2 just fine with my current network configuration, but with a different OS (I was on Windows XP, and recently installed Windows 7). My network card is a rather horrible Ralink Wireless card, which comes with its own configuration utility to set up network connections. Back when I was using XP, I would have similar issues unless I used the card's configuration utility instead of Windows XP's. While the configuration utility has a Windows 7 version, from reading some help files I tend to believe it hardly does anything other than provide an unnecessary coat of ugly paint over Windows 7's innate configuration.

If anyone has any suggestions, I would be grateful. In the event I break down and get another card (or punch holes in my walls for a wired connection), I'll be sure to update this with whatever effect such moves may have.

Solution 1:

I had a Ralink based Wireless card too and in particular with Windows 7 I had plenty of problems. High ping, disconnections, and so on.

My first suggestion is to try to connect directly to the modem with an Ethernet patch, only to verify that using this connection the ping problem is solved.

If it helps I can say that in my case I solved the problem without doing holes around, but I simply bought a couple of Netgear Powerline/Ethernet Adapters that worked perfectly.