Yep, you heard it correctly, Steam now works properly on my PC. After weeks, if not months, of trying to get it to work, I finally came across an online forum post that helped. If you are having trouble with Steam in Windows Vista working very slowly, failing to install a game (game cache files), failing to login / authenticate, you should give this fix a try.

You simply open a command prompt with Administrator privileges, and run the following command:

netsh interface tcp set global autotuninglevel=disabled

For more information, view the original post with details about how to open the "elevated" command prompt, and how to reverse this command should you have any trouble. After running this command on my system, I was able to install Steam, login, and install The Orange Box, without any trouble whatsoever. Everything was fast and smooth, as should be expected.

I hope this can save somebody from spending hours or days, frustrated out of their minds, trying to make Steam work smoothly on their Vista PC.

Valve, for their part, did attempt to help me via their support website, but as I've documented previously, their efforts were, for the most part, meagre, if not downright insulting at times. They simply regurgitate the information already available on the support website FAQs/knowledge base, and ask you the same questions over and over. A pity that they didn't recommend this solution during our lengthy conversation.

They tried to blame me a number of times for not doing things the way they say to, for setting up my router incorrectly, for having firewalls and other software that interferes with Steam, when in fact, the issue is a simple Windows Vista TCP stack problem. Not even a problem, really, but an incompatible "feature" (whch, in my opinion, might as well be a bug).

In any case, I can now play The Orange Box, have almost finished Half Life 2: Episode 1, and might get into a little Team Fortress 2 if I have the time. Unfortunately it's a bit too late, since the next barrage of new game releases starts next month (September) and I probably won't have much time to go back and play The Orange Box. It's refreshing that TF2 keeps getting updated, though, so we'll see if I can squeeze in a little bit of that, and hopefully complete Half Life 2: Episode 2.