You’ve got a work project that needs the old version of an app, and a personal project that needs the new one — so you need to run two versions of software on the same PC. Or you’re testing an update before rolling it out to a whole office. Whatever the reason, Windows usually fights you on this — most programs are built to open one instance, one version, at a time.
The good news: there are several reliable ways around that, and none of them require reinstalling Windows.
Quick answer: To run two versions of software on Windows, use a second local user account with “Run as different user,” a sandboxing tool like Sandboxie-Plus or Windows Sandbox, or a portable version of the app that runs without installing. For developer tools like Python or Node.js, a version manager (nvm, pyenv) is the cleanest fix. For software that truly can’t coexist, a virtual machine solves it every time.
Let’s go through each method, starting with the easiest.
Why Windows Blocks a Second Copy of the Same App
Before troubleshooting, it helps to know what’s actually happening. Most Windows programs use something called a single-instance lock — a small check the app runs at startup to see if it’s already active. If it is, the second launch either gets refused or just brings the existing window to the front.
This isn’t a Windows limitation so much as a developer choice. Some apps enforce it to prevent file conflicts (two copies writing to the same database at once), some do it to protect a paid license from being used twice, and some just never bothered to support multiple instances because nobody asked for it.
That distinction matters, because it tells you which fix will actually work. A simple re-launch trick only helps with apps that were built to allow multiple windows. Everything else needs a workaround that tricks Windows into treating the second copy as a completely separate thing — different user, different sandbox, different machine.
The Fastest Fix — Shift+Click to Reopen Office, Chrome, or Utilities
A surprising number of everyday programs already support multiple windows — you just haven’t triggered it the right way. Word, Excel, Chrome, Notepad, WordPad, Paint, Calculator, and Command Prompt all fall into this category.
Try this first:
- Open the app normally.
- Hold Shift and click its icon again in the taskbar or Start menu.
- A second, independent window opens — separate document, separate browsing session, separate everything.
This works because these apps aren’t checking for a single instance at all; they’re designed to support several open windows by default. It’s not “two versions” in the sense of two different software releases, but if your actual goal is two independent working sessions of the same program, this is the two-second solution and you can skip everything else below.
If the app you’re using isn’t in that list, or you specifically need two different releases of the same software (say, an old build alongside a new one), keep reading.
Create a Second User Account and “Run as Different User”
This is the most commonly recommended fix, and it works because Windows treats each user account as its own isolated environment — separate registry hive, separate app data folder, separate everything the single-instance check might be looking at.
Steps:
- Go to Settings > Accounts > Family & other users and add a new local account.
- Set a username and a password — a blank password will stop this method from working.
- Make the new account an administrator, otherwise it may only see apps installed “for all users” rather than the one tied to your main profile.
- Find the app in the Start menu, hold Shift, right-click, and choose Run as different user.
- Enter the second account’s credentials.
The app now launches under a separate identity, often letting both versions or both sessions run side by side without tripping the single-instance check.
A few caveats worth knowing up front: some apps will still block a second instance because the restriction is baked into the software itself, not tied to the user account. And if you see a “Windows cannot access the specified device, path, or file” error, it usually means the account you’re using doesn’t have permission to open that program — promoting it to administrator, or reinstalling the app “for all users,” typically fixes it.
Quick takeaway: free, built into Windows, no downloads — but hit-or-miss depending on how the individual app was coded.
Sandboxie-Plus vs. Windows Sandbox — True Isolation
When you need genuinely separate, self-contained copies of an app — different versions, different settings, different everything — sandboxing is the more dependable route.
Sandboxie-Plus runs a program inside a compartmentalized environment that never touches your real system files or registry. You can create multiple sandboxes, each holding a different version of the same app, and run them at the same time. To use it:
- Install Sandboxie-Plus.
- Right-click the app’s shortcut (or find it via Open File Location in the Start menu).
- Choose Run Sandboxed.
- Create a second sandbox for the other version and repeat.
Windows Sandbox, by contrast, is built into Windows 10 Pro/Enterprise and Windows 11 for free — no third-party download needed. It spins up a temporary, disposable virtual copy of Windows itself each time you open it, which is ideal for testing an installer you don’t fully trust, but it resets completely when closed, so it’s not meant for a version you want to keep using long-term.
| Sandboxie-Plus | Windows Sandbox | |
|---|---|---|
| Cost | Free | Free (built-in, Pro/Enterprise) |
| Persistence | Sandboxes persist between sessions | Resets on every close |
| Best for | Running two persistent app versions long-term | One-off testing of unfamiliar software |
| Setup | Third-party install | Enable via Windows Features |
If you want to keep both versions permanently available, Sandboxie-Plus is the better fit. If you just need to safely test something once, Windows Sandbox is faster to spin up.
Portable Apps — No Install, No Conflict
This is one of the most overlooked solutions, and often the simplest. A portable app runs directly from a folder without a formal installation — no registry entries, no shared system files, nothing for a second version to collide with.
Many popular programs offer an official portable build (look for “portable” on the developer’s download page), and sites like PortableApps.com package hundreds of common tools this way.
How to use it:
- Download the portable build of the version you need.
- Extract it to its own folder — for example,
C:\Apps\ProgramName-v1andC:\Apps\ProgramName-v2. - Run the
.exedirectly from each folder.
Because each version lives in its own self-contained folder with no shared registry keys, they simply don’t interfere with each other or with a normally installed copy. This is also the cleanest option if you want to keep a version on a USB drive or move it between machines without reinstalling.
The tradeoff: not every application publishes a portable build, and portable versions sometimes lag behind the latest release.
Running Two Versions of Python, Node.js, or Java
If you’re a developer, this whole problem shows up constantly — one project needs Python 3.9, another needs 3.12; one client needs an older Node.js LTS, another needs the newest release. Trying to solve this with reinstalls and PATH edits gets old fast.
The manual way (PATH variable): Install each version to its own folder (e.g., C:\Python39 and C:\Python312), then control which one runs by adjusting your system’s PATH environment variable order, or by calling the full file path directly instead of just typing python. This is exactly the same principle behind running 32-bit and 64-bit client software side by side — whichever path comes first in the PATH variable is the one that runs by default.
The better way (version managers): Tools built specifically for this job save a lot of manual PATH-editing:
- Python —
pyenv-winlets you install and switch between multiple Python versions with one command. - Node.js —
nvm-windowsdoes the same for Node, letting you runnvm use 18ornvm use 20per project. - Java —
jabbaor manually managingJAVA_HOMEper project achieves the same result.
These tools install versions into separate folders automatically and rewrite the active PATH for you, which is far less error-prone than doing it by hand — and it’s the standard approach most professional developers actually use rather than the manual account or sandbox tricks above.
Virtual Machines and Docker for Software That Refuses to Coexist
Some software genuinely cannot run two versions side by side no matter what trick you use — deep system-level tools, drivers, or enterprise software that installs services and shared components no sandbox can fully isolate. For these, go straight to full isolation.
Virtual machines (VirtualBox, VMware Workstation, or Windows’ built-in Hyper-V) run an entirely separate copy of Windows inside a window on your desktop. Install version one on your main system and version two inside the VM, and they never interact. This is the same principle behind the classic dual-boot solution, minus the hassle of rebooting your whole computer every time you want to switch.
Docker solves a related but slightly different problem: it’s built for server-side and command-line software rather than desktop apps, letting you run multiple isolated versions of a database, runtime, or backend service as lightweight containers rather than full virtual machines. If the “two versions” you’re trying to run are something like two versions of a database engine or a backend framework, Docker is usually lighter and faster to set up than a full VM.
Quick takeaway: slower to set up than the methods above, but the only option that guarantees zero conflict, every time.
Common Errors and Licensing Limits
A few honest caveats before you pick a method:
- “Windows cannot access the specified device, path, or file” almost always means a permissions issue with the second user account — promote it to administrator or reinstall the app for all users.
- Some apps detect a running copy and simply shut the second one down — this is intentional single-instance protection built into the software, and no Windows-level trick will bypass it. A sandbox or VM is the only reliable workaround in that case.
- Licensing matters. Running a second instance under a different user account or sandbox doesn’t create a second license out of nowhere — premium software with per-seat restrictions may still refuse to activate a second copy, and doing this to bypass a paid license agreement can violate the software’s terms of service. These methods are meant for legitimate use cases like testing, compatibility, or separate personal/work profiles — not license circumvention.
Final Thoughts: Run Two Versions of Software
Start with the free, built-in options — Shift+Click for apps that already support it, a second user account for everything else — before reaching for third-party tools. Move to Sandboxie-Plus or a portable build when you need something more permanent, and save virtual machines or Docker for the handful of programs that simply won’t share a system no matter what you try. If you’re a developer juggling language versions rather than desktop apps, skip straight to a version manager — it’ll save you the most time long-term.
FOR MORE HELPFUL GUIDES LIKE THIS, SEE MORE SOFTWARE TIPS AND EXPLORE MORE.
FAQ Section
Can I run two versions of the same software on Windows without conflicts?
Yes. Isolating each version with a separate user account, a sandbox like Sandboxie-Plus, or a portable build prevents the registry and file conflicts that normally stop two versions from coexisting.
Why does Windows only let me open one instance of an app?
Most apps include a single-instance lock in their code, usually to prevent file conflicts or protect a licensed seat. It’s a developer choice, not a Windows-wide restriction.
Is Sandboxie safe to use?
Yes — Sandboxie-Plus is widely used for isolating and testing software, including potentially untrusted downloads, because sandboxed apps can’t write to your real system files or registry.
What’s the difference between Windows Sandbox and Sandboxie?
Windows Sandbox is a free, built-in, disposable environment that resets every time you close it. Sandboxie-Plus is third-party software that lets you keep persistent sandboxes for long-term use.
Can I run two versions of Chrome at the same time?
Yes — Shift+Click the Chrome icon to open a second independent window, or use separate Chrome profiles for fully isolated sessions with different logins and extensions.
How do I run two versions of Python on Windows?
Install pyenv-win, then use it to install and switch between Python versions per project without manually editing your PATH each time.
Does using a second user account bypass software licensing?
No. It isolates the installation technically, but per-seat or per-license restrictions built into the software may still block a second active copy — check the license terms before relying on this for commercial software.
When should I use a virtual machine instead of a sandbox?
Use a VM when the software installs system-level drivers or services that a sandbox can’t fully isolate, or when you need true separation for testing on a completely clean environment.
