source-enginesteam
Steam won't let me have two instances running with the same user logged in.
Does that mean I cannot run a dedicated server on a PC (for example, for Left 4 Dead 2) and play from another machine?
Is there a way to run the dedicated server without running Steam? Is there a configuration option I'm missing?
As of the latest update to Steam, you can now PERMANENTLY remove games from your Steam account!
You can browse over your entire library and choose which software you'd like to permanently get rid of. But note, once you have removed a game from your library, it's gone permanently, so if later down the road you'd like it back you'll have to purchase it again.
You'll also need to watch out for some other issues. The thread linked above has noted that if the game is part of a bundle (HumbleBundle, etc.), removing one game from a "package" may require you to remove all the games from that specific bundle.
If you want to do this without starting Steam and logging in, you can modify the setting in the Windows registry. The autostart checkbox is directly tied to a registry key — simply deleting it is all the Steam client does when said checkbox is unchecked.
Navigate to HKCU\Software\Microsoft\Windows\CurrentVersion\Run and delete the Steam key. Or as a .reg file:
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run]
"Steam"=-
Best Answer
You don't need to have Steam running, just get the actual dedicated server (srcds).
This is a great site to get you started: Install SRCDS on Windows.