Run 2 Steam Accounts on One Computer

Need an extra DD account for storage space or want to run 2 steam games at once? Sandboxie makes it easy.

Intro

Ever play a game and wish you could have a second account for extra space, use as AFK shop or be able to trade with someone without having to leave your game? Sandboxie makes it easy.

Sandboxie allows you to run a self contained copy of steam on your computer along side your main install. Sandboxie has many other uses but I found it to be very useful when needing to run my second DD account and my other computer was otherwise engaged.

This guide is designed to help walk you through the setup and be able to use another DD account, or any other game account, on the same computer as your main account.

DISCLAIMER: This may not work for all games.

NOTE: This guide was mostly put together by another player but he didn't care to be named. Will gladly give him all the credit for this when he doesn't mind being mentioned

Requirements

• An extra steam account (this does not allow you to run your main account twice)
• An extra copy of the game. Family share wont work since you can play both at once. I recommend buying extra copies of your favorite game when steam has its sales or through humblebundle.

Folder Setup and Game Copy

Creating a new folder and copying the game files over is typically recommended but you can use the existing folder to save space if needed. Skip to next section if you want to use your current folder.

• Open up your Program Files directory where your Steam installation is (eg, C:\Program Files (x86)\)
• Create a new folder, I named mine "SteamSand" to make it simple.
• Now go into your normal Steam folder (eg, C:\Program Files (x86)\Steam\)
• Copy the folder "SteamApps" and file "Steam.exe" and Paste them into your SteamSand folder (eg, C:\Program Files (x86)\SteamSand\)
• Remember to COPY&PASTE, Do not MOVE. This can take a while depending on how many games you have installed. We'll leave this alone for now and come back later. 

Sandboxie Setup

• Now, Download SandBoxie from their website SandBoxie.com
• Install and Run SandBoxie
• When it's open, At the top click "Sandbox" and "Create New Sandbox"
• Name it whatever you want, I named mine "Steam" Then Click OK
• Once you've clicked OK, You'll see the new sandbox appear in the list, Right click on it and click "Sandbox Settings"
• In Settings, Click the + next to "Resource Access", Then the + next to "File Access", Now click "Full Access"
• Now click the "Add" button and Browse to the previously created "SteamSand" folder. Click on your "SteamSand" folder and Click OK.
• Click Apply and then OK
• There will be a popup stating you changes configuration blahblahblah, Just click OK.

How to Run

• Now go back to that "SteamSand" folder, Right click on "Steam.exe" and click "Run Sandboxed"
• You'll get a popup which will have you chose which Sandbox to run it with. Click on your "Steam" sandbox and click OK. (You may need to select the UAC check box as well)
• Steam will now open and prompt you to Login. Login with whatever account you want (Most likely your 2nd account)
• Steam will automatically download all the missing files we didn't copy.
• Done

Note: It is best to create a shortcut on your desktop to the "Steam.exe" file in your "SteamSand" folder and name it something like "Steam - Sandbox" as you will ALWAYS have to Right click -> Run Sandboxed.

Important Notes

There are several things to know about sandboxie that many have asked about since I wrote this originally.

• Sandboxie is free to use for 1 extra account. If you want to make 2 or more accounts using sanboxie then you must pay for it.
• You cannot host 2 private games on the same computer. You can join your main tavern with the second account and vice versa though.
• If running in Windowed mode, your cursor may move outside the window. I have accidentally closed my main window before when running around a map shooting. To get around this, play full screen on your main account.

REFERENCE: https://steamcommunity.com/sharedfiles/filedetails/?id=311943358