Start Steam offline without prompt?

[MeanJim]

I have a 2nd PC in my house that I have Steam on that has a few games that my niece likes to play. I put Steam into offline mode on that PC because Steam is usually online on my PC. I created shortcuts to the games and put them on the desktop so she can launch them from there. It has been working fine for months, when she would turn the system on and start a game, Steam would start minimized to the system tray and the game would just start.

This past Sunday night the cable and internet went out, and because of the labor day holiday it wasn't restored until this afternoon. My niece happened to be staying with me Sunday and Monday because my sister had to work on labor day. That PC was started before the internet went out Sunday, and she was able to play games on it before and after the outage. When she started the system to play a game Monday while the internet was out, Steam wouldn't start. I don't remember the exact error message, but it said something like Steam can't connect to the Steam network and offline mode is unavailable because login credentials aren't stored.

After my internet service was restored today, I started Steam on that PC and it prompted me for my password and started in online mode. I have Steam Guard enabled and it didn't have to be re-authorized. I knew there had been a few client updates since it had last connected, so I did a check for client updates, which it did. After Steam restarted, I checked once more for a client update, then set it to offline mode by clicking the Steam menu and selecting Go Offline. I disconnected the network cable and tried starting a Steam game. Now when I start a Steam game, Steam asks if you want to go online or continue offline.

TLDR:

First of all, why did Steam work in offline mode all this time until my connection was down and I really needed it to be offline? I know there have been issues with offline mode in the past, but I thought this had been fixed.

Second, why does it now prompt to continue offline or start online, and can I make it start offline without prompting? I will have to tell her to click the offline button when starting Steam games, but if she forgets and clicks to start Steam in online mode while it's running online on my PC, will it boot me off or not let her connect? The only thing I can think of is to set a firewall rule to block Steam just in case.

[drop | Gruni]

+1 - I have a few programs I use in VMware on my Mac and I don't want to be bothered by Steam all the time, just because I use the "real" Steam on Mac for gaming and communication.

[大aUp]

....

[osee1]

+1

[echo]

http://gaming.stackexchange.com/a/196778/138483 (steps for making it permanent - scroll up to the post he refers to for getting it to work in the first place)

[shinyshoes]

fyi for others - if this is for the purpose of not being online to friends when you login to steam: you can go to Friends & Chat in the bottom right corner of Steam, open it, click on the little gear icon in the top right corner of the friends list, & under the Friends List sub-section of the settings window, turn off "Sign in to friends when client starts".

[Phoenix]

Friends isn't even mentioned anywhere. What did you necro a post from almost a decade ago for?