I know of only one way that this can happen in windows, and has nothing to do with Steam other than their not-so-great decision to install all content into Program Files.
If you are on Windows 7 or Windows Vista, and you have UAC set to ON, then change it later to OFF, this can happen.
UAC does thing evil thing where if a program tries to write to a "protected" area like Program Files, EVEN IF YOU ARE ADMINISTRATOR, when you get a UAC prompt and give permission, it actually writes any files that would normally go into that directory into a "virtualized" directory somewhere else.
If you turn off UAC, that will no longer happen, and as an awesome bonus, it will no longer know about the files that it virtualized.
So in your case, if you had UAC on, installed a ton of games, then later got sick of UAC and turned it off, this would happen as you described.
See the second paragraph in "Features" in the article on User Account Control.
If you have done this and turn on UAC again, your content will come back, but be a TOTAL mess because if you've downloaded more stuff with UAC off, then that will be invisible when you turn UAC on, and vice versa.
this drove me a little crazy once before I realized what was happening.
i'm curious to know if this is your issue.
If the game is crashing the network, it is possible that the drivers are out of date OR the software used in the game is conflicting with his native drivers and causing a crash. My PC crashes a certain program whenever I plug my headphones in, as an example.
Things to try would include:
- Updating drivers for the networking device = check the manufacturers website
- Refreshing the Steam install (Verifying the game files)
- Trying a different network adapter (ie, a wireless adapter, if possible), and disable the cabled adapter during the test
- Check the Event Viewer to see if a certain program is causing the crash, or a certain service affected. If it is a service, force it to re-enable every time after a crash to see if that is a workaround for it (open services.msc, right click on the service, select properties, click on the recovery tab, and change all the drop down boxes at the top to "restart the service", although the 1 minute delay may be too much for it)
Unfortunately, there is no one-stop shop answer to solve this, just some testing. Good luck
Best Answer
I found that answer here and it seems like it helped a lot of people with the same problem.
I think it was a side effect of the anti-piracy protection implemented by Valve.
Portal 2 makes use of a Steamworks feature called "Custom Executable Generation": the Portal 2 executable (portal2.exe, plus some Steam-related DLLs) is not downloaded with the other game files. When the game is started for the first time after an update/new installation has been performed, Steam sends a request to the Steam servers so that the custom-made Portal 2 executable (tied to the Steam account) can be generated and then downloaded (the "Installing..." operation you can see during the first run is actually the executable download; also, the one or two files that can not be validated when you verify Portal 2's game cache integrity are the custom executable and libraries).
The latest update triggered this mechanism and, when many Portal 2 players tried to launch the game again, the Steam servers were probably overloaded by generation requests, hence the error message. I just attempted to launch the game again and it worked for me, if not just wait or choose another (less overloaded) content server from the Settings dialog.