BootStrap

Multi-Instance Launching

Last updated August 2026Applies to BootStrap v1.0.0+

Overview

By default, Roblox only allows one client to run on a PC at a time — try opening a second game and nothing happens. BootStrap's multi-instance support removes that restriction so you can run two, three or more clients simultaneously: play on one account while trading on another, keep an alt parked somewhere, or test your own experiences against each other.

Enabling multi-instance

  1. Open BootStrap and go to Settings → Integrations.
  2. Tick "Allow multiple Roblox instances".
  3. That's it. The change applies immediately — no restart needed.

With the option enabled, simply launch games as usual. Each new launch opens its own client alongside any that are already running.

How it works

The single-client restriction comes from a singleton mutex: when Roblox starts, it creates an operating-system lock object and refuses to continue if one already exists. With multi-instance enabled, BootStrap releases that mutex for every launch it performs, so each new client process starts up independently instead of detecting a previous instance and exiting.

This happens per-launch, entirely outside the game files — which is why toggling the option on and off is instant and completely reversible.

Limitations

  • Login sessions may behave unexpectedly. Both clients share login session behaviour, and how Roblox handles concurrent sign-ins can vary between updates. In practice most accounts stay signed in fine across instances, but occasional re-authentication prompts are normal.
  • Performance scales linearly. Every running client is a full 3D application competing for CPU, GPU and RAM. Two instances is comfortable on most modern machines; five is not. Expect frame drops if you overdo it.
  • Elevation matters. If you run one instance as administrator and another normally, Windows treats them as different security contexts and things can silently misbehave — see the troubleshooting notes.

Fair use reminder

Multi-instance exists for convenience — managing your own accounts, trading, development testing. Automating gameplay across many clients violates the Roblox Terms of Use and isn't what this feature is for.

Tips

  • Lower each client's graphics quality in the Roblox in-game menu before opening additional instances.
  • Use the FPS unlocker preset sparingly when running multiple clients — uncapped frame rates multiply GPU load fast.
  • If a second window seems to "not open", check whether the first was launched elevated (as admin) — see Troubleshooting → Multi-instance not working.