Fix ERROR_INSTALL_ALREADY_RUNNING (0x00000652)

This Error Shows Up When You Least Expect It

You try to install something — maybe a driver, an Office update, or a small utility — and Windows stops you cold with ERROR_INSTALL_ALREADY_RUNNING (0x00000652). The full message reads: "Another installation is already in progress. Complete that installation before proceeding with this install."

This usually happens when a previous installation didn't finish cleanly. Maybe it hung, maybe you force-killed it, or maybe the Windows Installer service is holding onto a stale lock. I've seen this after a failed Windows Update, a botched .NET Framework install, or even a simple printer driver that crashed midway.

Don't restart your PC yet — that's a sledgehammer when you just need a screwdriver. Let's walk through fixes from quickest to most thorough.

Fix #1: Kill the Stuck Installer (30 seconds)

Open Task Manager (Ctrl+Shift+Esc). Click More details if you see the simple view. Look for msiexec.exe on the Processes tab. If you see one, right-click and End task.

Also check under Background processes for anything named Windows Installer or msiexec. Sometimes there are multiple instances. Kill all of them.

Now try your installation again. If it works, you're done. If not, move on.

Fix #2: Restart the Windows Installer Service (2 minutes)

If killing the process didn't help, the service itself might be in a bad state. Here's how to reset it:

1. Press Win+R, type services.msc, and hit Enter.
2. Scroll down to Windows Installer. Right-click it and choose Stop.
3. Wait 10 seconds. Then right-click again and choose Start.

This clears the internal lock. Try your install now. If the service won't stop, or starts and immediately stops, you might have a corrupted service state — but that's rare. Usually a simple restart does the trick.

Fix #3: Clean the Installer Queue from Command Line (5 minutes)

Sometimes a partial install leaves a pending transaction in the MSI database. You can flush it manually.

Open Command Prompt as Administrator (right-click Start > Windows Terminal (Admin) or Command Prompt (Admin)). Then run:

msiexec /unregister

Wait a few seconds, then:

msiexec /regserver

This re-registers the Windows Installer engine and clears any orphaned transactions. I've used this dozens of times on Windows 10 and 11 — it's saved me from rebooting many a machine.

After this, try your installation again. If you still get the error, we need to check the MSI buffer directly.

Fix #4: Check and Clear the MSI Lock File (10 minutes)

The Windows Installer service uses a mutex — a lock file — to prevent two installers from running at once. Sometimes this mutex gets stuck even though no installer is running.

Open an elevated Command Prompt and run:

sc query msiserver

Look at the STATE line. It should say RUNNING. If it says STOPPED, start the service with:

sc start msiserver

Then, to be extra safe, clear any pending MSI operations:

msiexec /x {00000000-0000-0000-0000-000000000000} /qn

That dummy GUID won't uninstall anything — it just forces the installer to check for a clean state. You might see a brief error about the product not being found; that's fine. It means the lock is gone.

Now try your install one more time.

Fix #5: Reboot and Kill Stubborn Processes (30 seconds after reboot)

If nothing above worked, reboot. But here's the trick: when Windows comes back, before you launch anything else, open Task Manager and check for msiexec.exe again. Some laptops with OEM software (like Dell SupportAssist or HP Support Assistant) trigger silent installers at startup. If you see one, kill it, then run your install right away.

I've seen machines where a background driver updater from the manufacturer keeps stealing the installer lock. Kill that process and you're golden.

Still Stuck? Here's the Nuclear Option (15+ minutes)

If you've done all the above and the error won't budge, you might have a deeper corruption. Run the System File Checker:

sfc /scannow

Let it finish. Then run DISM to fix the system image:

DISM /Online /Cleanup-Image /RestoreHealth

This takes 10-20 minutes depending on your drive speed. After both complete, reboot and try the fix again from the top. In my experience, this clears out the majority of stuck installer states that survive a simple restart.

One last thing: if you're on a corporate laptop with Group Policy or software deployment, talk to your IT admin. Sometimes the error comes from a forced install that's pending from the network — you can't override that from your user account.

That's it. Start with killing msiexec.exe, work your way down. 9 times out of 10, the first fix is all you need. Good luck.