Can't play two Steam instances anymore...

I use Aster ( to share the same computer (Windows 10 x64) with another user. I use 2 terminals: 

  1. Terminal 1 is the main one.
  2. Terminal 2 is the additional terminal.

Using Aster, it is not possible for two terminals to use Steam at the same time: if one terminal runs Steam, it kills Steam from the other terminal and vice versa.

To remedy the problem, Aster's technical team recommended Sandboxie, where I could normally run Steam on the main terminal and on the second terminal, Steam should be run through Sandboxie.

This was working, but maybe due to the latest Steam update now, every time I'm playing any Steam games on terminal 1, I can't play any games on terminal 2.

Even running Steam terminal 2 with Sandboxie, it is now asking to PURCHASE the games.

In order to play ANY GAME on terminal 2, I first have to quit the current game on terminal 1.

What now?

  • Try running one steam instance in offline mode, or disable internet for it through

    sandbox setting - restrictions - internet access

  • In reply to qwer asdf:

    Thanks for your response, but, Steam will not start with internet restrictions...

    Also, I can't find how to run Steam offline, could you please tell me the steps?

  • In reply to Rogério Dec:

    maybe you need to change the settings in sandboxie. there's a step where you're supposed to make steam run in some special way:

    open sandboxie > make a new sandbox> name it steam or something obvious > right click on its icon > settings > click + on Resource Access > File Access > Direct Access > Add Program > "Open / Select File" > (find steam , probably located at C:\Program Files (x86)\Steam\Steam.exe) > select it in the filebrowser (click open) > hit ok a few times > right click on the sandboxie icon you made > "Run Sandboxed" > "Run Any Program" > find steam again and launch it

    (or you can listen to a 13 year old british kid explaining that if thats how you like doing things


    i never had the problem you had, hopefully that settings change was enough to fix your problem.


    i have the same setup:

    >windows 10 home

    >1 pc, 2 monitors, 

    >using aster, sandboxie;

    1) main pc terminal runs steam with sandboxie on steam account A

    2) secondary pc terminal runs steam normally on steam account B


    2.5) i did have an unmentioned problem where the sandboxie steam had like a black screen for everything, but that is fixed by going to program files > sandboxie and changing all of the .exe's in there to be ran as administrator (properties>compatibility>check the box "run this program as an administrator"). after that, you have to find the .exe of every game you wanna play and do the same to that.


    3) it works


    4) i tested same thing except this time both terminals use steam account A

    5) opened "the resistance" on one and csgo on the other

    6) close largely meaningless sandboxie error messages

    7) it works

    8) turns out changing the game's .exe to be admin is not required for all games


    are u sure youre running the steam in sandbox mode? i didnt have your problem at all